Biosensing strategy based on photocurrent quenching of quantum dots via energy resonance absorption  

作　　者：Guangming Wen Peng Wang Wenwen Tu Jianping Lei Huangxian Ju 

机构地区：[1]State Key Laboratory of Analytical Chemistry for Life Science [2]School of Chemistry and Chemical Engineering, Nanjing University

出　　处：《Science China Chemistry》2015年第5期879-884,共6页中国科学（化学英文版）

基　　金：financially supported by the National Basic Research Program of China(2010CB732400);the National Natural Science Foundation of China(21375060,21135002,21121091)

摘　　要：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.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 pro- posed 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.

关 键 词：energy resonance absorption photocurrent quenching photoelelctrochemistry BIOSENSING DNA 

分 类 号：O657.1[理学—分析化学]