A novel photoelectrochemical sensor based on photocathode of PbS quantum dots utilizing catalase mimetics of bio-bar-coded platinum nanoparticles/G-quadruplex/hemin for signal amplification.
Photocathode based on p-type PbS quantum dots (QDs) combing a novel signal amplification strategy utilizing catalase (CAT) mimetics was designed and utilized for sensitive photoelectrochemical (PEC) detection of DNA. The bio-bar-coded Pt nanoparticles (NPs)/G-quadruplex/hemin exhibited high CAT-like activity following the Michaelis-Menten model for decomposing H2O2 to water and oxygen, whose activity even slightly exceeded that of natural CAT. The bio-bar-code as a catalytic label was conjugated onto the surface of PbS QDs modified electrodes through the formed sandwich-type structure due to DNA hybridization. Oxygen in situ generated by the CAT mimetics of the bio-bar-code of Pt NPs/G-quadruplex/hemin acted as an efficient electron acceptor of illuminated PbS QDs, promoting charge separation and enhancing cathodic photocurrent. Under optimal conditions, the developed PEC biosensor for target DNA exhibited a dynamic range of 0.2pmol/L to 1.0nmol/L with a low detection limit of 0.08pmol/L. The high sensitivity of the method was resulted from the sensitive response of PbS QDs to oxygen and the highly efficient CAT-like catalytic activity of the bio-bar-coded Pt NPs/G-quadruplex/hemin.
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China; State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210093, PR China. Electronic address: glwang@jiangnan.edu.cn.
Guang-Li
GL
Wang
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Kang-Li
KL
Liu
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Jun-Xian
JX
Shu
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Tian-Tian
TT
Gu
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Xiu-Ming
XM
Wu
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Yu-Ming
YM
Dong
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, PR China.
Zai-Jun
ZJ
Li
D040761:Biomimetic Materials / Q000737:chemistry; D015374:Biosensing Techniques / Q000295:instrumentation*; D002374:Catalase / Q000737:chemistry; D003217:Conductometry / Q000295:instrumentation*; D004247:DNA / Q000032:analysis / Q000235:genetics*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry*; D007854:Lead / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010783:Photometry / Q000295:instrumentation; D010984:Platinum / Q000737:chemistry; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry
D018036:Selenium Compounds; C088065:lead selenide; D007854:Lead; D010984:Platinum; D006427:Hemin; D004247:DNA; D002374:Catalase
Catalase; Enzyme mimetics; PbS quantum dots; Photocathode; Photoelectrochemical biosensor