title: CdS/MoS2 heterojunction-based photoelectrochemical DNA biosensor via enhanced chemiluminescence excitation.
abstract: This work developed a CdS/MoS2 heterojunction-based photoelectrochemical biosensor for sensitive detection of DNA under the enhanced chemiluminescence excitation of luminol catalyzed by hemin-DNA complex. The CdS/MoS2 photocathode was prepared by the stepwise assembly of MoS2 and CdS quantum dots (QDs) on indium tin oxide (ITO), and achieved about 280% increasing of photocurrent compared to pure CdS QDs electrode due to the formation of heterostructure. High photoconversion efficiency in the photoelectrochemical system was identified to be the rapid spatial charge separation of electron-hole pairs by the extension of electron transport time and electron lifetime. In the presence of target DNA, the catalytic hairpin assembly was triggered, and simultaneously the dual hemin-labeled DNA probe was introduced to capture DNA/CdS/MoS2 modified ITO electrode. Thus the chemiluminescence emission of luminol was enhanced via hemin-induced mimetic catalysis, leading to the physical light-free photoelectrochemical strategy. Under optimized conditions, the resulting photoelectrode was proportional to the logarithm of target DNA concentration in the range from 1 fM to 100 pM with a detection limit of 0.39 fM. Moreover, the cascade amplification biosensor demonstrated high selectivity, desirable stability and good reproducibility, showing great prospect in molecular diagnosis and bioanalysis.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Zang
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China. Electronic address: jpl@nju.edu.cn.
authors.forename: Jianping
authors.initials: J
authors.lastname: Lei
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Huangxian
authors.initials: H
authors.lastname: Ju
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D019187:Cadmium Compounds / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008163:Luminescent Measurements / Q000295:instrumentation*; D008982:Molybdenum / Q000737:chemistry*; D055096:Optical Devices; D010087:Oxides / Q000737:chemistry; D010777:Photochemistry / Q000295:instrumentation; D015203:Reproducibility of Results; D018036:Selenium Compounds / Q000737:chemistry; D012666:Semiconductors; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000295:instrumentation* / Q000379:methods
chemical_list: D019187:Cadmium Compounds; D010087:Oxides; D018036:Selenium Compounds; D008982:Molybdenum; D004247:DNA; C058667:cadmium selenide
keywords: Biosensors; DNA detection; MoS(2); Photoelectrochemistry; Quantum dots