A new facile method for preparing water-soluble near-infrared （NIR）-emitting PbS quantum dots （QDs） is proposed by using N-acetyl-L-cysteine （NAC, a derivate of L-cysteine） as its stabilizer. The influence of th...A new facile method for preparing water-soluble near-infrared （NIR）-emitting PbS quantum dots （QDs） is proposed by using N-acetyl-L-cysteine （NAC, a derivate of L-cysteine） as its stabilizer. The influence of the precursor Pb/S molar ratio, the Pb/NAC molar ratio, and the pH of original solution on optical properties is explored. Results show that aqueous PbS QDs with strong NIR fluorescence can be prepared and their photoluminescence emission peaks can be tuned from 895 nm to 970 nm. Studies indicate that such aqueous QDs have a potential application in biomedical imaging, especially in noninvasive in vivo fluorescence imaging. In addition, the resulting PbS QDs are further characterized by a transmission electron microscopy and X-ray diffraction analysis.展开更多
Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor marker...Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as ceils and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carders would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability.展开更多
Vibrio parahaemolyticus is the leading causal agent of human acute gas- troenteritis. Real-time accurate detection means is the key to prevention and control of its spread. This study provided a novel detection strate...Vibrio parahaemolyticus is the leading causal agent of human acute gas- troenteritis. Real-time accurate detection means is the key to prevention and control of its spread. This study provided a novel detection strategy for realizing rapid and specific determination of V. parahaemolyticus by labeling its monoclonal antibody （Ab） with quantum dots （QDs）. The results showed that the fluorescence of these QDs-Ab bioconjugates was quenched by graphene oxide （GO） to produce a bacteri- um capture probe. And the optimal quenched concentration of GO was 60 ng/ml. When the bacterium capture probe was exposed to the target, green color fluores- cence was turned on by releasing the QDs-Ab due to the antibody antigen combi- nation. The detection limit of V. parahaemolyticus was 104 CFU/ml based on 3 times signal-to-noise ratio. The specificity of the FRET sensor towards V. para- haemolyticus was examined by comparing with controls such as V. splendidus, V. alginolyticus, Edwardsiella tarda and Aeromonas hydrophila with the same condition. The controls couldn＇t cause obvious fluorescence alteration, while the target resulted in significant fluorescence enhancement. This strategy could be further used as a universal method for any bacterial determination by changing the conjugated antibod- ies in early disease diagnosis. Therefore, the sensor has good potential to expand its application to the early diagnosis and determination of bacteria.展开更多
Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the developm...Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the development of a novel approach for cancer detection is urgent,and real-time monitoring is crucial in revealing its underlying biological mechanisms.With the optical and chemical advantages of quantum dots(QDs),QD-based nanotechnology is helpful in constructing a biomedical imaging platform for cancer behavior study.This review mainly focuses on the application of QD-based nanotechnology in cancer cell imaging and tumor microenvironment studies both in vivo and in vitro,as well as the remaining issues and future perspectives.展开更多
This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biologica...This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed.展开更多
In this paper, we mainly study the preparation of an optical biosensor based on porous silicon(PSi) Bragg mirror and its feasibility for biological detection. The quantum dot(QD) labeled biotin was pipetted onto strep...In this paper, we mainly study the preparation of an optical biosensor based on porous silicon(PSi) Bragg mirror and its feasibility for biological detection. The quantum dot(QD) labeled biotin was pipetted onto streptavidin functionalized PSi Bragg mirror samples, the affinity reaction between QD labeled biotin and streptavidin in PSi occurred, so the QDs were indirectly connected to the PSi. The fluorescence of QD enhanced the signal of biological reactions in PSi. The performance of the sensor is verified by detecting the fluorescence of the QD in PSi. Due to the fluorescence intensity of the QDs can be enhanced by PSi Bragg mirror, the sensitivity of the PSi optical biosensor will be improved.展开更多
A new concept of energy resonance absorption for photocurrent quenching was proposed using a system of quantum dots(QDs) and the matched dye. The QDs were used as the photocurrent producer, and the dye had an absorpti...A new concept of energy resonance absorption for photocurrent quenching was proposed using a system of quantum dots(QDs) and the matched dye. The QDs were used as the photocurrent producer, and the dye had an absorption band overlapped with that of the QDs, which led to the resonance absorption of the excitation energy and thus decreased the photocurrent of QDs. By using porphyrin and fluorscein isothiocyanate isomer I as the resonance absorption dyes, the proposed mechanism was proved by UV-Vis spectra, photoluminescence spectra and photocurrent-to-wavelength response, respectively. The interaction of the absorption-matched dye with biomolecule could be conveniently used to introduce it into the photocurrent quenching system, leading to a simple switch-off biosensing method for detection of the biomolecule. As example, a label-free method was proposed for photoelectrochemical detection of target DNA. This method showed a detection range from 6.0 to 600 nmol/L with a detection limit of 2.5 nmol/L. The result demonstrated that the photocurrent quenching via energy resonance absorption not only contributed to the theoretical study of photoelectrochemistry, but also provided a universal tool for photoelectrochemical biosensing.展开更多
Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formati...Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formation of sulfur nanodots with desired performances.This synthetic strategy allowed for simultaneous size control from 3.2 to 5.6 nm,thus tuning the emission color from ultraviolet(UV)to deep blue(342±430 nm),and for the suppression of unwanted nonradiative recombination centers and deep level emission.The luminescence mechanism and quantum confinement effect of the synthesized sulfur nanodots were investigated by optical spectroscopy and theoretical calculations.These results show promise toward the application of sulfur nanodots in UV optoelectronics,biomedical treatments,and sterilization.展开更多
基金Supported by the National Natural Science Foundation of China (30800257,30700799)the Scien-tific Research Starting Foundation for Introduced Talented Persons of China Pharmaceutical University~~
文摘A new facile method for preparing water-soluble near-infrared （NIR）-emitting PbS quantum dots （QDs） is proposed by using N-acetyl-L-cysteine （NAC, a derivate of L-cysteine） as its stabilizer. The influence of the precursor Pb/S molar ratio, the Pb/NAC molar ratio, and the pH of original solution on optical properties is explored. Results show that aqueous PbS QDs with strong NIR fluorescence can be prepared and their photoluminescence emission peaks can be tuned from 895 nm to 970 nm. Studies indicate that such aqueous QDs have a potential application in biomedical imaging, especially in noninvasive in vivo fluorescence imaging. In addition, the resulting PbS QDs are further characterized by a transmission electron microscopy and X-ray diffraction analysis.
基金the grants from the New-Century Excellent Talents Sup-porting Program of the Ministry of Education of China (No. NCET-04-0669)the Foundation for the Author of National Excellent Doctoral Dis-sertation of China (No. 200464)+2 种基金the Wuhan Innovation Study Project (No. 20066002054)the Natural Science Foundation of China (No. 20675058)the Science Fund for Creative Research Groups (No. 20621502), NSFC.
文摘Tumor markers have been of vital importance in cancer diagnosis, treatment and monitoring. However, the sensitivity of current tumor markers for early diagnosis is low, reducing the clinical usefulness of tumor markers. Quantum dots are new fluorescent nanoparticles with unique photophysical and chemical properties, thus having a great potential impact on the investigation of cancer pathogenesis, early diagnosis, targeted therapy, prognosis and monitoring, when combined with tumor markers. The current research is focused on the detection of specific tumor markers or molecules based on tangible carriers such as ceils and tissues. One of the most promising clinical applications would be to explore the potential of this highly sensitive labeling technique for the detecting and imagining tumor markers in serum and other body fluids, where some progresses have already been made recently. How to detect early cancer based solely on invisible carders would be the next step of quantum dots bio-probes in clinical use, so as to develop a new detection technique with greater sensitivity, specificity, rapidity and availability.
基金Supported by Shandong Scientific and Technological Development Program(2014GHY115024)~~
文摘Vibrio parahaemolyticus is the leading causal agent of human acute gas- troenteritis. Real-time accurate detection means is the key to prevention and control of its spread. This study provided a novel detection strategy for realizing rapid and specific determination of V. parahaemolyticus by labeling its monoclonal antibody （Ab） with quantum dots （QDs）. The results showed that the fluorescence of these QDs-Ab bioconjugates was quenched by graphene oxide （GO） to produce a bacteri- um capture probe. And the optimal quenched concentration of GO was 60 ng/ml. When the bacterium capture probe was exposed to the target, green color fluores- cence was turned on by releasing the QDs-Ab due to the antibody antigen combi- nation. The detection limit of V. parahaemolyticus was 104 CFU/ml based on 3 times signal-to-noise ratio. The specificity of the FRET sensor towards V. para- haemolyticus was examined by comparing with controls such as V. splendidus, V. alginolyticus, Edwardsiella tarda and Aeromonas hydrophila with the same condition. The controls couldn＇t cause obvious fluorescence alteration, while the target resulted in significant fluorescence enhancement. This strategy could be further used as a universal method for any bacterial determination by changing the conjugated antibod- ies in early disease diagnosis. Therefore, the sensor has good potential to expand its application to the early diagnosis and determination of bacteria.
基金supported by the Academic Award for Excellent Ph.D.Candidates Funded by the Ministry of Education of China(No.5052011303014)the National Natural Science Foundation of China(No.81171396)+1 种基金the Science Fund for Creative Research Groups of the National Natural Science Foundation of China(Nos.20621502 and 20921062)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(No.4103005).
文摘Cancer is a major threat to public health in the 21st century because it is one of the leading causes of death worldwide.The mechanisms of carcinogenesis,cancer invasion,and metastasis remain unclear.Thus,the development of a novel approach for cancer detection is urgent,and real-time monitoring is crucial in revealing its underlying biological mechanisms.With the optical and chemical advantages of quantum dots(QDs),QD-based nanotechnology is helpful in constructing a biomedical imaging platform for cancer behavior study.This review mainly focuses on the application of QD-based nanotechnology in cancer cell imaging and tumor microenvironment studies both in vivo and in vitro,as well as the remaining issues and future perspectives.
基金support of the National Natural Science Foun-dation of China (20821063 & 50972058)supported by the National Basic Research Program of China (2011CB933502)
文摘This review presents a simple introduction on the unique properties and general synthesis of quantum dots (QDs) in which we lay emphasis on the optical applications in the biological system. The detection of biological molecules such as DNA, protein and enzyme, the cell-based analysis and in vivo animal imaging are mainly discussed.
基金supported by the National Natural Science Foundation of China(Nos.61575168 and 61665012)the Xinjiang Science and Technology Project(No.201412112)
文摘In this paper, we mainly study the preparation of an optical biosensor based on porous silicon(PSi) Bragg mirror and its feasibility for biological detection. The quantum dot(QD) labeled biotin was pipetted onto streptavidin functionalized PSi Bragg mirror samples, the affinity reaction between QD labeled biotin and streptavidin in PSi occurred, so the QDs were indirectly connected to the PSi. The fluorescence of QD enhanced the signal of biological reactions in PSi. The performance of the sensor is verified by detecting the fluorescence of the QD in PSi. Due to the fluorescence intensity of the QDs can be enhanced by PSi Bragg mirror, the sensitivity of the PSi optical biosensor will be improved.
基金financially supported by the National Basic Research Program of China(2010CB732400)the National Natural Science Foundation of China(21375060,21135002,21121091)
文摘A new concept of energy resonance absorption for photocurrent quenching was proposed using a system of quantum dots(QDs) and the matched dye. The QDs were used as the photocurrent producer, and the dye had an absorption band overlapped with that of the QDs, which led to the resonance absorption of the excitation energy and thus decreased the photocurrent of QDs. By using porphyrin and fluorscein isothiocyanate isomer I as the resonance absorption dyes, the proposed mechanism was proved by UV-Vis spectra, photoluminescence spectra and photocurrent-to-wavelength response, respectively. The interaction of the absorption-matched dye with biomolecule could be conveniently used to introduce it into the photocurrent quenching system, leading to a simple switch-off biosensing method for detection of the biomolecule. As example, a label-free method was proposed for photoelectrochemical detection of target DNA. This method showed a detection range from 6.0 to 600 nmol/L with a detection limit of 2.5 nmol/L. The result demonstrated that the photocurrent quenching via energy resonance absorption not only contributed to the theoretical study of photoelectrochemistry, but also provided a universal tool for photoelectrochemical biosensing.
基金financially supported by A*STAR(AME-IRG-A20E5c0083)the National Natural Science Foundation of China(52006005)。
文摘Bright tunable light emission in the short wavelength range from sulfur nanodots was demonstrated with a photoluminescence quantum yield(PLQY)of up to 59.4%.A fission-aggregation mechanism was proposed for the formation of sulfur nanodots with desired performances.This synthetic strategy allowed for simultaneous size control from 3.2 to 5.6 nm,thus tuning the emission color from ultraviolet(UV)to deep blue(342±430 nm),and for the suppression of unwanted nonradiative recombination centers and deep level emission.The luminescence mechanism and quantum confinement effect of the synthesized sulfur nanodots were investigated by optical spectroscopy and theoretical calculations.These results show promise toward the application of sulfur nanodots in UV optoelectronics,biomedical treatments,and sterilization.
