One-pot hydrothermal route to fabricate nitrogen doped graphene/Ag-TiO2: Efficient charge separation, and high-performance "on-off-on" switch system based photoelectrochemical biosensing.
Charge separation is crucial for increasing the performances of semiconductor-based materials in many photoactive applications. In this paper, we designed novel nanocomposites consisting of TiO2 nanocrystals, Ag nanoparticles (NPs) and nitrogen doped graphene (NGR) via a facile one-pot hydrothermal route. The as-prepared ternary nanocomposites exhibited enhanced photoelectrochemical (PEC) performances owing to the introduction of Ag NPs and NGR, which increase the excitons' lifetime and improve the charge transfer. In particular, it is shown by means of the transient-state surface photocurrent responses that the photocurrent intensity of the as-fabricated composites exhibited 18.2 times higher than that of pristine TiO2. Based on the robust photocurrent signal, a new kind of "on-off-on" PEC aptasensor was established with the assistance of Pb(2+) aptamer, which integrates the advantages of low background signal and high sensitivity. Under optimal conditions, a wide linear response for Pb(2+) detection was obtained from 1pM to 5nM as well as a detection limit down to 0.3pM. With its simplicity, selectivity, and sensitivity, this proposed strategy shows great promise for Pb(2+) detection in food and environment analysis.
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Ding
D
Jiang
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Xiaojiao
X
Du
School of Pharmacy, Jiangsu University, Zhenjiang 212013, PR China.
Danyang
D
Chen
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Lei
L
Zhou
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Wei
W
Chen
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Yaqi
Y
Li
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Nan
N
Hao
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Jing
J
Qian
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
Qian
Q
Liu
Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: wangkun@ujs.edu.cn.
Kun
K
Wang
D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods; D002413:Cations, Divalent / Q000032:analysis; D055664:Electrochemical Techniques / Q000379:methods; D004784:Environmental Monitoring / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis*; D005504:Food Analysis / Q000379:methods; D005506:Food Contamination / Q000032:analysis*; D006108:Graphite / Q000737:chemistry*; D007854:Lead / Q000032:analysis*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D009584:Nitrogen / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000032:analysis
D052157:Aptamers, Nucleotide; D002413:Cations, Divalent; D004785:Environmental Pollutants; D014867:Water; C009495:titanium dioxide; D007854:Lead; D012834:Silver; D006108:Graphite; D014025:Titanium; D009584:Nitrogen
Ag nanoparticle; Efficient charge separation; Nitrogen doped graphene; On-off-on; Photoelectrochemical biosensing; TiO(2) nanocrystal