Owing to its photonic band gap(PBG)and slow light effects,aniline black(AB)-poly(vinylidene fluoride)(PVDF)inverse opal(IO)photonic crystal(PC)was constructed to promote the utility of light and realize photothermal s...Owing to its photonic band gap(PBG)and slow light effects,aniline black(AB)-poly(vinylidene fluoride)(PVDF)inverse opal(IO)photonic crystal(PC)was constructed to promote the utility of light and realize photothermal synergetic catalysis.As a highly efficient reaction platform with the capability of restricting heat,a microreactor was introduced to further amplify the photothermal effects of near infrared(NIR)radiation.The photocatalytic efficiency of ZnO/0.5AB-PVDF IO(Z0.5A)increases 1.63-fold compared to that of pure ZnO film under a full solar spectrum,indicating the effectiveness of synergetic promotion by slow light and photothermal effects.Moreover,a 5.85-fold increase is achieved by combining Z0.5A with a microreactor compared to the film in a beaker.The photon localization effect of PVDF IO was further exemplified by finite-difference time-domain(FDTD)calculations.In conclusion,photonic crystal-microreactor enhanced photothermal catalysis has immense potential for alleviating the deteriorating water environment.展开更多
Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy det...Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidasecatalyzed reaction of glucose with oxygen, by oxidation at a microelectrode. However, （micro）electrodes in direct contact with physiological sample are subject to electrode fouling, which leads to signal drift, decreased reproducibility and shortened detector lifetimes. Moreover, there are a few species present in the body （e.g. ascorbic acid, uric acid） which can undergo oxidation at the same applied potential as hydrogen peroxide. These species can thus inter- fere with the glucose measurement, reducing detection specificity. The rationale for exploring chemiluminescence as opposed to amperometric detection is thus to attempt to improve the lifetime and reproducibility of glucose analysis for monitoring purposes, while reducing interference caused by other chemicals in the body. The study reported here represents a first step in this direction, namely the realization of a microfluidic device with integrated silicon photodiode for chemiluminescence detection of glucose. This microflow device uses a chaotic mixing approach to perform enzymatic conversion of glucose, followed by reaction of the hydrogen peroxide produced with luminol to produce light at 425 nm. The chemil reaction is catalyzed by horseradish peroxidase in the presence of iodophenol. The performance of the fabricated chip was characterized to establish optimal reaction conditions with respect to sample and reagent flow rates, pH, and concentrations. A linear calibra- tion curve was obtained for current response as a function of glucose concentration in the clinically relevant range between 2 and 10 mM, with a sensitivity of 39 pA/mM （R = 0.9963, one device, n = 3） and a limit of detection of 230 ktM （S/N - 3）.展开更多
As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers...As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers with tailorable morphologies and functions from a multi-injection microfluidic approach.The microfibers were generated by introducing PeQDs precursors into each barrel of the inner capillary array and mixing them in the spindle middle channel,where the poly(vinylidene fluoride)(PVDF)dissolved in N,N-dimethyl formamide(DMF)was also injected as their sheath fluid.During this process,the PeQDs were in situ synthesized with the connection of precursor cations and anions in the core fluid;while the PVDF formed solidified microfibers to encapsulate PeQDs with the fast dispersion of DMF into the outer aqueous solution.Thus,the good encapsulation of PeQDs was achieved in PVDF microfibers,which effectively protected them from different hostile environments.Because of the highly tunable spinning processes,the microfibers exhibited controllable diameters and helical geometric structures,and the encapsulated PeQDs could yield adjustable emission peaks.Based on the PeQDs microfibers,we have explored their potential as luminescent materials in barcodes and as flexible photodetectors,which make such microfibers highly versatile for different areas.展开更多
文摘Owing to its photonic band gap(PBG)and slow light effects,aniline black(AB)-poly(vinylidene fluoride)(PVDF)inverse opal(IO)photonic crystal(PC)was constructed to promote the utility of light and realize photothermal synergetic catalysis.As a highly efficient reaction platform with the capability of restricting heat,a microreactor was introduced to further amplify the photothermal effects of near infrared(NIR)radiation.The photocatalytic efficiency of ZnO/0.5AB-PVDF IO(Z0.5A)increases 1.63-fold compared to that of pure ZnO film under a full solar spectrum,indicating the effectiveness of synergetic promotion by slow light and photothermal effects.Moreover,a 5.85-fold increase is achieved by combining Z0.5A with a microreactor compared to the film in a beaker.The photon localization effect of PVDF IO was further exemplified by finite-difference time-domain(FDTD)calculations.In conclusion,photonic crystal-microreactor enhanced photothermal catalysis has immense potential for alleviating the deteriorating water environment.
文摘Chemiluminescence detection was developed as an alternative to amperometric detection for glucose analysis in a portable, microfluidicsbased continuous glucose monitoring system. Amperometric detection allows easy determination of hydrogen peroxide, a product of the glucose oxidasecatalyzed reaction of glucose with oxygen, by oxidation at a microelectrode. However, （micro）electrodes in direct contact with physiological sample are subject to electrode fouling, which leads to signal drift, decreased reproducibility and shortened detector lifetimes. Moreover, there are a few species present in the body （e.g. ascorbic acid, uric acid） which can undergo oxidation at the same applied potential as hydrogen peroxide. These species can thus inter- fere with the glucose measurement, reducing detection specificity. The rationale for exploring chemiluminescence as opposed to amperometric detection is thus to attempt to improve the lifetime and reproducibility of glucose analysis for monitoring purposes, while reducing interference caused by other chemicals in the body. The study reported here represents a first step in this direction, namely the realization of a microfluidic device with integrated silicon photodiode for chemiluminescence detection of glucose. This microflow device uses a chaotic mixing approach to perform enzymatic conversion of glucose, followed by reaction of the hydrogen peroxide produced with luminol to produce light at 425 nm. The chemil reaction is catalyzed by horseradish peroxidase in the presence of iodophenol. The performance of the fabricated chip was characterized to establish optimal reaction conditions with respect to sample and reagent flow rates, pH, and concentrations. A linear calibra- tion curve was obtained for current response as a function of glucose concentration in the clinically relevant range between 2 and 10 mM, with a sensitivity of 39 pA/mM （R = 0.9963, one device, n = 3） and a limit of detection of 230 ktM （S/N - 3）.
基金the National Key Research and Development Program of China(2020YFA0908200)the National Natural Science Foundation of China(52073060 and 61927805)+2 种基金the Natural Science Foundation of Jiangsu(BE2018707)Shenzhen Fundamental Research Program(JCYJ20190813152616459)China Postdoctoral Science Foundation(2020M680652)。
文摘As perovskite quantum dots(PeQDs)are performing their outstanding characteristics,incremental efforts have been devoted to such materials.Here,inspired by the spider spinning process,we present novel PeQDs microfibers with tailorable morphologies and functions from a multi-injection microfluidic approach.The microfibers were generated by introducing PeQDs precursors into each barrel of the inner capillary array and mixing them in the spindle middle channel,where the poly(vinylidene fluoride)(PVDF)dissolved in N,N-dimethyl formamide(DMF)was also injected as their sheath fluid.During this process,the PeQDs were in situ synthesized with the connection of precursor cations and anions in the core fluid;while the PVDF formed solidified microfibers to encapsulate PeQDs with the fast dispersion of DMF into the outer aqueous solution.Thus,the good encapsulation of PeQDs was achieved in PVDF microfibers,which effectively protected them from different hostile environments.Because of the highly tunable spinning processes,the microfibers exhibited controllable diameters and helical geometric structures,and the encapsulated PeQDs could yield adjustable emission peaks.Based on the PeQDs microfibers,we have explored their potential as luminescent materials in barcodes and as flexible photodetectors,which make such microfibers highly versatile for different areas.
