In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter w...In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter were modified using poly-adenine-tailed Pb^(2+)-specific 8–17 DNAzyme to form a spherical and functional Protmin. Substrate strands modified with a fluorophore at the 50 end and a quencher at the 30 end were bound to DNAzyme. Pb^(2+) facilitated cleavage of DNAzyme to release the fluorophore-modified short strands to generate fluorescence. We observed rapid kinetics of the Protmin nanosensor, for which the typical assay time was 10 min.Further, we demonstrated the Protmin nanosensor could readily enter living cells and respond to Pb^(2+) in the intracellular environment. The broad of range of Protmindesigns will be useful for advancing biological and medical applications.展开更多
We report a novel technique to enhance the ultraviolet (UV) photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconduct...We report a novel technique to enhance the ultraviolet (UV) photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconductivity and the time response of the ZnO nanowire sensor with either Schottky or Ohmic contacts are significantly improved by electrifying the nanowire sensors using an alternating current at the frequency of megahertz. An integrated UV sensor incorporating ZnO nanowires with a constant current mode driving circuit is developed, which demonstrates promising sensitivity and time response to UV illumination with a low power consumption.展开更多
Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensi...Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensing performance remain the concerned issues,thereby limiting the scale-up in deploying air quality tracking networks.Herein,we report a standalone-like smart device that can remotely track the variation of air pollutants in a power-saving way.Brevity,the created smart device demonstrated satisfactory selectivity(against six kinds of representative exhaust gases or air pollutants),desirable response magnitude(164–100 ppm),and acceptable response/recovery rate(52.0/50.5 s),as well as linear response relationship to NO2.After aging for 2 weeks,the created device exhibited relatively stable sensing performance more than 3 months.Moreover,a photoluminescence-enhanced light fidelity(Li-Fi)telecommunication technique is proposed and the Li-Fi communication distance is significantly extended.Conclusively,our reported standalone-like smart device would sever as a powerful sensing platform to construct high-performance and low-power consumption air quality wireless sensor networks and to prevent air pollutant-induced diseases via a more effective and low-cost approach.展开更多
The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diamet...The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diameter 200-300 nm) were used to measure, in situ, the balance between NO and ONOO-produced by human umbilical vein endothelial cells (HUVEC’s). The amperometric nanosensors were placed 5 ± 2 μm from the surface of the endothelial cells and the concentration of NO and ONOO- was measured at 630 mV and -300 mV (vs Ag/AgCl) respectively. Normal, functional, endothelial cells produced maximal 450 ± 25 nmol.L-1 of NO and 180 ± 15 nmol.L-1 of ONOO- in about 3 s, after stimulation with calcium ionophore. The in situ measurements of NO and ONOO- were validated using nitric oxide synthase inhibitor L-NMMA, ONOO- scavenger Mn(III) porphyrin, and superoxide dismutase (PEG-SOD). The ratio of NO concentration to ONOO- concentration ([NO]/[ONOO-]) was introduced for quantification of both, the redox balance and the level of the nitroxidative stress in the endothelium. [NO]/[ONOO-] was 2.7 ± 0.1 in a functional endothelium. The model of the dysfunctional endothelium was made by the treatment of HUVEC’s with angiotensin II for 20 min. Dysfunctional HUVEC’s produced only 115 ± 15 nmol.L-1 of NO, but generated a significantly higher concentration of ONOO- of 490 ± 30 nmol.L-1. The [NO]/[ONOO-] ratio decreased to 0.23 ± 0.14 in the dysfunctional endothelium. Electrochemical nanosensors can be effectively used for in situ monitoring of changing levels of nitroxidative/ oxidative stress, and may be useful in early medical diagnosis of the cardiovascular system.展开更多
Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton...Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton nanosensors(PNSs)with different pH sensitive ranges could satisfy different research requirements.Here we report a facile method to build a PNS with a neutral to basic pH sensitive range,in which the commercial pH indicator,fluoresceinamine(FA),was covalently coupled to the carboxylic-rich amphiphilic polymer(AP)coated gold nanoparticles(AuNPs).展开更多
Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA an...Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA and Fe(Ⅱ)-phenanthroline system,an elegant ratiometric fluorescent nanosensor,without noble metal nanoparticle,was designed for the detection of CIO-and IO4-.Fe(Ⅱ)-phenanthroline complex is used as fluorescent absorber,which can quench green light of UCNPs with gradually varied extent depending on the concentration of Fe(Ⅱ).The linear zone extends to 800 and 120μmol/L while the detection limit is 1.30 and 0.58μmol/L for NaCIO and NaIO_(4),respectively.Finally,the nanosensor was successfully applied to detect NaCIO and NaIO4spiked in milk,spring water,and tap water with good recoveries.展开更多
This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication tec...This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.展开更多
Aiming at the poor stability of attitude control of mobile robot mechanism, a kind of attitude stabilitycontrol system of mobile robot mechanism based on nanodisplacement sensor is designed.In the hardware part, a hyd...Aiming at the poor stability of attitude control of mobile robot mechanism, a kind of attitude stabilitycontrol system of mobile robot mechanism based on nanodisplacement sensor is designed.In the hardware part, a hydraulic drive is used to control the action posture of the mobile robot,a nanodisplacement sensor is used to collect the walking data of the robot, and serial communicationof the upper computer is used to convert the data into electrical signals to realise therobot posture control. In the software part, the mathematical coordinate system of robot walkingis constructed, and the rotating posture of the robot is controlled by the Euler angle. Theexperimental results show that the control performance of the designed system is stable andthe control precision is high, which can realise the attitude stabilisation control of the mobilerobot.展开更多
Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leadin...Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.展开更多
In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group...In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group,employing fluorescein isothiocyanate(FITC) doped as the pH-sensitive dye and Tris(2,2'-bipyidyl) dichlororuthenium(II) hexahydrate(RuBpy) doped as reference dye. The pH change of the Hela cells induced by vincristine sulfate has been monitored in vivo,in situ and real time by use of the ratiometric pH nanosensors. The experimental results show that the pH of the apoptotic Hela cells induced by vincristine sulfate has been acidified from 7.11 to 6.51,and the percentage of intra-cellular acidification is correlated with the induced concentration and incubation time of the vincristine sulfate. The further study of the percentage of intracellular acidification and the percentage of apop-tosis of Hela cells at the same time reveals that apoptosis of Hela cells induced by vincristine sulfate is preceded by intracellular acidification. These results would provide theoretical foundation for the therapy of cancer through interfering the pH of cells by use of vincristine sulfate or other anti-cancer drugs.展开更多
Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo det...Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo detection of nudeic acid targets using a promising type of surface-enhanced Raman scattering (SERS) nanosensor implanted in the skin of a large animal model (pig). The in vivo nanosensor used in this study involves the "inverse molecular sentinel" detection scheme using plasmonics-active nanostars, which have tunable absorption bands in the near infrared region of the "tissue optical window", rendering them efficient as an optical sensing platform for in vivo optical detection. Ex vivo measurements were also performed using human skin grafts to demonstrate the detection of SERS nanosensors through tissue. In this stud, a new core--shell nanorattle probe with Raman reporters trapped between the core and shell was utilized as an internal standard system for self-calibration. These results illustrate the usefulness and translational potential of the SERS nanosensor for in vivo biosensing.展开更多
Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of le...Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of lead in water is highly required and demands efficient, sensitive, cost-effective, and reliable lead detection methods. This study reports a label-free colorimetric nanosensor that uses unmodified gold nanoparticles (AuNPs) as indicators to enable rapid and ultra-sensitive detection of lead in environmental water. The 8-17 DNAzyme was truncated in this study to facilitate the detachment of single-stranded DNA fragments after substrate cleavage in the presence of Pb「. The detached fragments were adsorbed over AuNPs and protected against salt concentration-induced aggregation. Accordingly, high Pb^2+ would result in rapid color change from blue to pink. The established sensing principle achieved a sensitive limit of detection of 0.2×10^-9mol/L Pb^2+. with a linear working range of two orders of magnitude from 0.5×10^-9mol/L to 5×10^-9mol/L. The selectivity of the nanosensor was demonstrated by evaluating the interfering metal ions. The developed nanosensor can serve as a substitute for the rapid analysis and monitoring of trace lead levels under the drinking water distribution system and even other environmental water samples.展开更多
Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with...Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.展开更多
The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes(ARGs) is a public health concern that highlights the need for improved monitoring ...The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes(ARGs) is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene(ARG) detection in ARG-spiked effluent from four wastewater treatment plants(WWTPs). The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength([MgCl_2] 〈 50 m M), and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM(≈ 4 × 10~7 genes/μL), even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.展开更多
Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatibl...Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatible and impractical for intracellular K^(+)probing.Herein,we report a supersmall biomimetic K^(+)nanosensor to serve as a transmembrane vector capable of electrochemically detecting intracellular K^(+)in a minimally invasive manner.展开更多
A switchable room-temperature phosphorescence(RTP) nanosensor based on an MPA-capped Mn-dopedZnS QDs/CTAB composite system(MPA=3-mercaptopropionic acid; CTAB=cetyltrimethyl ammonium bromide;QDs=quantum dots) was e...A switchable room-temperature phosphorescence(RTP) nanosensor based on an MPA-capped Mn-dopedZnS QDs/CTAB composite system(MPA=3-mercaptopropionic acid; CTAB=cetyltrimethyl ammonium bromide;QDs=quantum dots) was established for the detection of biotin. The phosphorescence intensity of QDs/CTAB couldbe regularly quenched with the increase of biotin. Under optimal conditions, this method yielded two linear ranges of2-20 μg/L and 20-140 μg/L with respective correlation coefficients of 0.993 and 0.990, as well as a detection limitof 0.93 μg/L. Therefore, the analytical potential of the proposed nanosensor was evaluated by detecting biotin inurine and biotin tablets. This approach yielded satisfactory results because of the effective elimination of backgroundfluorescence and light scattering from the sample matrix. This approach provides a practical method for biotin detec-tion.展开更多
A new kind of nonmetallic nanosensors based on surface-enhanced Raman spectroscopy(SERS)have been successfully prepared by the assembly of α-Fe_(2)O_(3) nanoparticles(NPs)onto clean quartz surface via the cross-linke...A new kind of nonmetallic nanosensors based on surface-enhanced Raman spectroscopy(SERS)have been successfully prepared by the assembly of α-Fe_(2)O_(3) nanoparticles(NPs)onto clean quartz surface via the cross-linker of hexamethylene diisocyanate(HDI).The resultant substrates have been characterized by electron micrographs,which show that the α-Fe_(2)O_(3) NPs distribute on the modified surface uniformly with a monolayer or sub-monolayer structure.4-mercaptopyridine(4-Mpy)and 2-mercaptobenzothiazole(2-MBT)molecules have been used as SERS probes to estimate the detection efficiency of the α-Fe_(2)O_(3) thin films.The SERS experiments show that it is possible to record high quality SERS spectra from probe molecules on the α-Fe_(2)O_(3) thin films at sub-micromolar(<10^(–6) mol/L)concentration.These results indicate that the highly ordered,uniformly roughed,highly sensitive and low-cost α-Fe_(2)O_(3) thin films are excellent candidates for nonmetallic SERS-active nanosensors.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21390414 and 21605087)the Chinese Academy of Sciences(No.QYZDJ-SSW-SLH031)+2 种基金the China Postdoctoral Science Foundation funded project(No.BX201700123)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications(No.NY215058)the Natural Science Fund for Colleges and Universities in Jiangsu Province(16KJB150032)
文摘In this study, we designed and applied proteinmimicking nanoparticles(Protmin) as an intracellular nanosensor for in vivo detection of lead ions(Pb^(2+)).Monodispersed gold nanoparticles(Au NPs) of 13 nm in diameter were modified using poly-adenine-tailed Pb^(2+)-specific 8–17 DNAzyme to form a spherical and functional Protmin. Substrate strands modified with a fluorophore at the 50 end and a quencher at the 30 end were bound to DNAzyme. Pb^(2+) facilitated cleavage of DNAzyme to release the fluorophore-modified short strands to generate fluorescence. We observed rapid kinetics of the Protmin nanosensor, for which the typical assay time was 10 min.Further, we demonstrated the Protmin nanosensor could readily enter living cells and respond to Pb^(2+) in the intracellular environment. The broad of range of Protmindesigns will be useful for advancing biological and medical applications.
基金Project supported by the National Natural Science Foundation of China (Grant No. 91123017)
文摘We report a novel technique to enhance the ultraviolet (UV) photosensitivity of a ZnO nanosensor with ZnO nanowires bridged on micromachined metallic electrodes. The experimental results reveal that the photoconductivity and the time response of the ZnO nanowire sensor with either Schottky or Ohmic contacts are significantly improved by electrifying the nanowire sensors using an alternating current at the frequency of megahertz. An integrated UV sensor incorporating ZnO nanowires with a constant current mode driving circuit is developed, which demonstrates promising sensitivity and time response to UV illumination with a low power consumption.
基金the financial support for this research from the National Key Research and Development Program of China(Grant No.2017YFA0205301)National Natural Science Foundation of China(Grant No.61771267,61774106)+6 种基金Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(Grant No.BX2020208)Shanghai Natural Science Foundation(Grant No.86973)Natural Science Foundation of Ningbo City(Grant No.2017A610229)National Postdoctoral Program for Innovative Talents(Grant No.BX20190205)Special fund for science and technology innovation of Shanghai Jiao Tong University(Grant No.YG2017MS70)Shanghai Municipal Bureau of Economy and Information Technology(Grant No.XC-ZXSJ-02-2016-05)China Postdoctoral Science Foundation.
文摘Remote tracking the variation of air quality in an effective way will be highly helpful to decrease the health risk of human short-and long-term exposures to air pollution.However,high power consumption and poor sensing performance remain the concerned issues,thereby limiting the scale-up in deploying air quality tracking networks.Herein,we report a standalone-like smart device that can remotely track the variation of air pollutants in a power-saving way.Brevity,the created smart device demonstrated satisfactory selectivity(against six kinds of representative exhaust gases or air pollutants),desirable response magnitude(164–100 ppm),and acceptable response/recovery rate(52.0/50.5 s),as well as linear response relationship to NO2.After aging for 2 weeks,the created device exhibited relatively stable sensing performance more than 3 months.Moreover,a photoluminescence-enhanced light fidelity(Li-Fi)telecommunication technique is proposed and the Li-Fi communication distance is significantly extended.Conclusively,our reported standalone-like smart device would sever as a powerful sensing platform to construct high-performance and low-power consumption air quality wireless sensor networks and to prevent air pollutant-induced diseases via a more effective and low-cost approach.
文摘The cytoprotective messenger nitric oxide (NO) and cytotoxic peroxynitrite (ONOO-) are the main components of oxidative stress and can be generated by endothelial cells. A tandem of electrochemical nanosensors (diameter 200-300 nm) were used to measure, in situ, the balance between NO and ONOO-produced by human umbilical vein endothelial cells (HUVEC’s). The amperometric nanosensors were placed 5 ± 2 μm from the surface of the endothelial cells and the concentration of NO and ONOO- was measured at 630 mV and -300 mV (vs Ag/AgCl) respectively. Normal, functional, endothelial cells produced maximal 450 ± 25 nmol.L-1 of NO and 180 ± 15 nmol.L-1 of ONOO- in about 3 s, after stimulation with calcium ionophore. The in situ measurements of NO and ONOO- were validated using nitric oxide synthase inhibitor L-NMMA, ONOO- scavenger Mn(III) porphyrin, and superoxide dismutase (PEG-SOD). The ratio of NO concentration to ONOO- concentration ([NO]/[ONOO-]) was introduced for quantification of both, the redox balance and the level of the nitroxidative stress in the endothelium. [NO]/[ONOO-] was 2.7 ± 0.1 in a functional endothelium. The model of the dysfunctional endothelium was made by the treatment of HUVEC’s with angiotensin II for 20 min. Dysfunctional HUVEC’s produced only 115 ± 15 nmol.L-1 of NO, but generated a significantly higher concentration of ONOO- of 490 ± 30 nmol.L-1. The [NO]/[ONOO-] ratio decreased to 0.23 ± 0.14 in the dysfunctional endothelium. Electrochemical nanosensors can be effectively used for in situ monitoring of changing levels of nitroxidative/ oxidative stress, and may be useful in early medical diagnosis of the cardiovascular system.
基金Supported by grants from the National Natural Science Foundation of China(Nos.21171086 and 81160213)Inner Mongolia Grassland Talent(No.108-108038)+1 种基金Inner Mongolia Autonomous Region Natural Science Foundation(No.2013MS1121)the Inner Mongolia Agricultural University(Nos.211-109003 and 211-206038)
文摘Bio-nanosensors(Bio-NSs)have attracted much attention recently due to their unique properties.Among all of the bio-NSs,the intracellular proton sensor is significant for biomedicine studies and clinic diagnosis.Proton nanosensors(PNSs)with different pH sensitive ranges could satisfy different research requirements.Here we report a facile method to build a PNS with a neutral to basic pH sensitive range,in which the commercial pH indicator,fluoresceinamine(FA),was covalently coupled to the carboxylic-rich amphiphilic polymer(AP)coated gold nanoparticles(AuNPs).
基金Project supported by the Natural Science Foundation of Shandong Province(ZR2016EMM20,ZR2019PEM012)National Natural Science Foundation of China(21808114)the Foundation(ZZ20190310)of State Key Laboratory of Biobased Material and Green Papermaking。
文摘Oxidizing CIO^(-)and IO_(4)^(-)exist widely in environment and are closely related to the health of organisms.Accordingly,fast,sensitive,and direct detection of the two species is significant.Using IFE in UCNPs@PAA and Fe(Ⅱ)-phenanthroline system,an elegant ratiometric fluorescent nanosensor,without noble metal nanoparticle,was designed for the detection of CIO-and IO4-.Fe(Ⅱ)-phenanthroline complex is used as fluorescent absorber,which can quench green light of UCNPs with gradually varied extent depending on the concentration of Fe(Ⅱ).The linear zone extends to 800 and 120μmol/L while the detection limit is 1.30 and 0.58μmol/L for NaCIO and NaIO_(4),respectively.Finally,the nanosensor was successfully applied to detect NaCIO and NaIO4spiked in milk,spring water,and tap water with good recoveries.
基金This work was supported by the Czech Science Foundation(GAČR,No.22-14886S)the MCIN/AEI/10.13039/501100011033(No.PID2019-107697RBC42(ERDF A way of making Europe)).
文摘This work focuses on the fabrication and characterization of Chemical Field-Effect Transistor(ChemFET)gas nanosensor arrays based on single nanowire(SNW).The fabrication processes include micro and nanofabrication techniques enabled by a combination of ultraviolet(UV)and e-beam lithography to build the ChemFET structure.Results show the integration and connection of SNWs across the multiple pairs of nanoelectrodes in the ChemFET by dielectrophoresis process(DEP)thanks to the incorporation of alignment windows(200-300 nm)adapted to the diameter of the NWs.Measurements of the SNW ChemFET array's output and transfer characteristics prove the influence of gate bias on the drain current regulation.Tests upon hydrogen(H_(2))and nitrogen dioxide(NO_(2))as analyte models of reducing and oxidizing gases show the ChemFET sensing functionality.Moreover,results demonstrate better response characteristics to H_(2)when the ChemFET operates in the subthreshold regime.The design concepts and methods proposed for fabricating the SNW-based ChemFET arrays are versatile,reproducible,and most likely adaptable to other systems where SNW arrays are required.
基金the Research and Practice of School-Enterprise Cooperative Education Model of Automobile Body Maintenance Technology Based on productive training base(No.2019JZ016)Henan Provincial Central Guiding local science and technology development fund support project in 2022-Application and promotion of unmanned plant protection vehicle technology based on intelligent network.
文摘Aiming at the poor stability of attitude control of mobile robot mechanism, a kind of attitude stabilitycontrol system of mobile robot mechanism based on nanodisplacement sensor is designed.In the hardware part, a hydraulic drive is used to control the action posture of the mobile robot,a nanodisplacement sensor is used to collect the walking data of the robot, and serial communicationof the upper computer is used to convert the data into electrical signals to realise therobot posture control. In the software part, the mathematical coordinate system of robot walkingis constructed, and the rotating posture of the robot is controlled by the Euler angle. Theexperimental results show that the control performance of the designed system is stable andthe control precision is high, which can realise the attitude stabilisation control of the mobilerobot.
基金We thank the Natural Science Foundation of Hubei Province of China(2023AFB330)the China Postdoctoral Science Foundation(2022M721275)the Hubei Provincial Market Supervision Administration Science and Technology Program Project(Hbscjg-KJ2021002)for financial support.
文摘Dairy products have become one of the most prevalent daily foods worldwide,but safety concerns are rising.In dairy farming,unscrupulous traders misuse antibiotics to treat some diseases such as mastitis in cows,leading to antibiotic residues in dairy products.Rapid,sensitive,and simple detection methods for antibiotic residues are particularly important for food safety in dairy products.Traditional detection technology can effectively detect antibiotics,but there are defects such as complicated pre-treatment and high cost.Biosensors are widely used in food safety due to fast detection speed,low detection cost,strong anti-interference ability,and suitability for the field application.Nevertheless,these sensors often fail to trigger the signal conversion output due to low target concentration.To cope with this issue,some high-efficiency signal amplification systems can be introduced to improve the detection sensitivity and linear range of biosensors.In this review,we focused on:(i)Sources and toxicity of major antibiotics in animal-derived foods.(ii)Nanomaterial-mediated biosensors for real-time detection of target antibiotics in animal-derived foods.(iii)Signal amplification techniques to increase the sensitivity of biosensors.Finally,future prospects and challenges in this research field are discussed.
基金Supported by the Key Project of National Natural Science Foundation of China (Grant No. 20135010)the National Key Basic Research Program of China (Grant No. 2002CB513100-10)+3 种基金the Key Technology Research and Development Program of China (Grant No. 2003BA310A16)the High-Tech Research and Development Program of China (Grant No. 2003AA302250)the International Cooperation Key Project of Science and Technology Ministry (Grant No. 2003DF000039)the National Natural Science Foundation of China (Grant No. 20405005)
文摘In this paper,the relationship of intracellular acidification and apoptosis in Hela cells induced by vin-cristine sulfate has been studied by use of the ratiometric pH nanosensors that have been developed by our group,employing fluorescein isothiocyanate(FITC) doped as the pH-sensitive dye and Tris(2,2'-bipyidyl) dichlororuthenium(II) hexahydrate(RuBpy) doped as reference dye. The pH change of the Hela cells induced by vincristine sulfate has been monitored in vivo,in situ and real time by use of the ratiometric pH nanosensors. The experimental results show that the pH of the apoptotic Hela cells induced by vincristine sulfate has been acidified from 7.11 to 6.51,and the percentage of intra-cellular acidification is correlated with the induced concentration and incubation time of the vincristine sulfate. The further study of the percentage of intracellular acidification and the percentage of apop-tosis of Hela cells at the same time reveals that apoptosis of Hela cells induced by vincristine sulfate is preceded by intracellular acidification. These results would provide theoretical foundation for the therapy of cancer through interfering the pH of cells by use of vincristine sulfate or other anti-cancer drugs.
文摘Although nanotechnology has led to important advances in in vitro diagnostics, the development of nanosensors for in vivo detection remains very challenging. Here, we demonstrated the proof-of-principle of in vivo detection of nudeic acid targets using a promising type of surface-enhanced Raman scattering (SERS) nanosensor implanted in the skin of a large animal model (pig). The in vivo nanosensor used in this study involves the "inverse molecular sentinel" detection scheme using plasmonics-active nanostars, which have tunable absorption bands in the near infrared region of the "tissue optical window", rendering them efficient as an optical sensing platform for in vivo optical detection. Ex vivo measurements were also performed using human skin grafts to demonstrate the detection of SERS nanosensors through tissue. In this stud, a new core--shell nanorattle probe with Raman reporters trapped between the core and shell was utilized as an internal standard system for self-calibration. These results illustrate the usefulness and translational potential of the SERS nanosensor for in vivo biosensing.
文摘Water pollution accidents, such as the Flint water crisis in the United States, caused by lead contamination have raised concern on the safety of drinking water distribution systems. Thus, the routine monitoring of lead in water is highly required and demands efficient, sensitive, cost-effective, and reliable lead detection methods. This study reports a label-free colorimetric nanosensor that uses unmodified gold nanoparticles (AuNPs) as indicators to enable rapid and ultra-sensitive detection of lead in environmental water. The 8-17 DNAzyme was truncated in this study to facilitate the detachment of single-stranded DNA fragments after substrate cleavage in the presence of Pb「. The detached fragments were adsorbed over AuNPs and protected against salt concentration-induced aggregation. Accordingly, high Pb^2+ would result in rapid color change from blue to pink. The established sensing principle achieved a sensitive limit of detection of 0.2×10^-9mol/L Pb^2+. with a linear working range of two orders of magnitude from 0.5×10^-9mol/L to 5×10^-9mol/L. The selectivity of the nanosensor was demonstrated by evaluating the interfering metal ions. The developed nanosensor can serve as a substitute for the rapid analysis and monitoring of trace lead levels under the drinking water distribution system and even other environmental water samples.
基金This work was supported by the Shenzhen Municipal Science and Technology Innovation Council(JCYJ20180504165819965)the National Natural Science Foundation of China(No.21874063)The authors acknowledge the technical support from SUSTech Core Research Facilities。
文摘Compared with conventional water-soluble fluorescence probes,pH-sensitive fluorescent nanosensors based on hydrophobic indicators remain largely unexplored.We report here the unique pH response of the nanosensors with a hydrophobic indicator(Ch3,a Nile Blue derivative)in polymeric nanoparticles(NPs).At the aqueous-organic interface of the NPs,spectral overlap and dye accumulation caused significant Förster resonance energy transfer(FRET)not only between the protonated and deprotonated Ch3(hetero-FRET),but also between the protonated and deprotonated Ch3 themselves(homo-FRET).The pH response was simulated according to an interfacial response mechanism and the dynamic range was found to depend on the size of the NPs and dye distribution(Kp).Therefore,adjusting the size of the NPs and the local dye concentration gave rise to a series of dynamic sensing ranges with apparent pKa values from 2.7 to 9.6 based on a single indicator.The nanosensors were successfully delivered to HeLa cells to monitor subcellular pH values in the endosomes and lysosomes.Based on cellular calibrations,the average pH in the organelles were determined to be ca.4.7.Moreover,the pH neutralization process during lysosome membrane permeabilization(LMP)induced by hydrogen peroxide stimulation was also successfully visualized with the nanosensors.
基金supported by US National Science Foundation grants CBET-1133746 and OISE-1545756support for MVR was provided by the Virginia Tech Graduate School
文摘The global propagation of environmental biocontaminants such as antibiotic resistant pathogens and their antibiotic resistance genes(ARGs) is a public health concern that highlights the need for improved monitoring strategies. Here, we demonstrate the environmental stability and applicability of an oligonucleotide-functionalized gold nanosensor. The mec A ARG was targeted as model biocontaminant due to its presence in clinically-relevant pathogens and to its emergence as an environmental contaminant.mec A-specific nanosensors were tested for antibiotic resistance gene(ARG) detection in ARG-spiked effluent from four wastewater treatment plants(WWTPs). The mec A-specific nanosensors showed stability in environmental conditions and in high ionic strength([MgCl_2] 〈 50 m M), and high selectivity against mismatched targets. Spectrophotometric detection was reproducible with an LOD of 70 pM(≈ 4 × 10~7 genes/μL), even in the presence of interferences associated with non-target genomic DNA and complex WWTP effluent. This contribution supports the environmental applicability of a new line of cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.
基金supported by the National Natural Sci-ence Foundation of China(grant nos.21327902,21675080,and 21974059)the Natural Science Founda-tion of Jiangsu Province(grant no.BK20170073)the Excellent Research Program of Nanjing University(no.ZYJH004).
文摘Intracellular potassium ions(K^(+))play pivotal roles in many physiological processes.Several K^(+)sensors have been developed for probing cellular K^(+)fluctuations.Nevertheless,the existing solutions are incompatible and impractical for intracellular K^(+)probing.Herein,we report a supersmall biomimetic K^(+)nanosensor to serve as a transmembrane vector capable of electrochemically detecting intracellular K^(+)in a minimally invasive manner.
文摘A switchable room-temperature phosphorescence(RTP) nanosensor based on an MPA-capped Mn-dopedZnS QDs/CTAB composite system(MPA=3-mercaptopropionic acid; CTAB=cetyltrimethyl ammonium bromide;QDs=quantum dots) was established for the detection of biotin. The phosphorescence intensity of QDs/CTAB couldbe regularly quenched with the increase of biotin. Under optimal conditions, this method yielded two linear ranges of2-20 μg/L and 20-140 μg/L with respective correlation coefficients of 0.993 and 0.990, as well as a detection limitof 0.93 μg/L. Therefore, the analytical potential of the proposed nanosensor was evaluated by detecting biotin inurine and biotin tablets. This approach yielded satisfactory results because of the effective elimination of backgroundfluorescence and light scattering from the sample matrix. This approach provides a practical method for biotin detec-tion.
基金This work was supported by the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.09KJD150002)Zhenjiang Science and Technology Bureau(No.GJ2006006)Jiangsu University High-grade Specialty Person Scientific Research Foundation(No.10JDG114).
文摘A new kind of nonmetallic nanosensors based on surface-enhanced Raman spectroscopy(SERS)have been successfully prepared by the assembly of α-Fe_(2)O_(3) nanoparticles(NPs)onto clean quartz surface via the cross-linker of hexamethylene diisocyanate(HDI).The resultant substrates have been characterized by electron micrographs,which show that the α-Fe_(2)O_(3) NPs distribute on the modified surface uniformly with a monolayer or sub-monolayer structure.4-mercaptopyridine(4-Mpy)and 2-mercaptobenzothiazole(2-MBT)molecules have been used as SERS probes to estimate the detection efficiency of the α-Fe_(2)O_(3) thin films.The SERS experiments show that it is possible to record high quality SERS spectra from probe molecules on the α-Fe_(2)O_(3) thin films at sub-micromolar(<10^(–6) mol/L)concentration.These results indicate that the highly ordered,uniformly roughed,highly sensitive and low-cost α-Fe_(2)O_(3) thin films are excellent candidates for nonmetallic SERS-active nanosensors.