The visible light-driven and self-powered photoelectrochemical biosensor for organophosphate pesticides detection based on nitrogen doped carbon quantum dots for the signal amplification

• Published in: Electrochimica acta 2019-02, Vol.296, p.627-636
• Main Authors: Cheng, Wenjie, Zheng, Zengyao, Yang, Jianying, Chen, Min, Yao, Qingwei, Chen, Yaowen, Gao, Wenhua
• Format: Article
• Language: English
• Subjects: Biosensors; Carbon; Catalysis; Chinese cabbage; Chlorpyrifos; Electrodes; High fluorescence quantum yield; Holes (electron deficiencies); Indium tin oxides; Nanoparticles; Nitrogen; Organophosphates; Organophosphorus pesticides; Pesticides; Photoelectric effect; Photoelectric emission; Photoelectrochemical detection; Quantum dots; Substrates; Titanium dioxide; Upconversion light; Visible light absorption
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2018.11.086

A novel visible light driven self-powdered photoelectrochemical (PEC) biosensor was constructed for organophosphorus pesticides (OPs). The biosensor was prepared by taking indium tin oxide (ITO) as the substrate, titanium dioxide (TiO2) nanoparticles as the photoactive substrate material, nitrogen-doped carbon quantum dots (NCQDs) as the photosensitizer and acetylcholinesterase (AChE) as the biorecognition molecule. Because of the excellent optical performances of NCQDs, the photocurrent response of the NCQD/TiO2/ITO electrode were improved obviously compared with TiO2/ITO electrode. The AChE immobilized on the surface of the PEC biosensor can catalytic hydrolysis of acetylcholine chloride (ATCl) to generate thiocholine, which can serve as the electron donor to enhance the separation of the photogenerated electron-hole pairs, therefore, the photocurrent response of the PEC biosensor elevated greatly. The bioactivity of the AChE was inhibited by OPs where chlorpyrifos was used as the model, the production of the thiocholine was declined, leading to a reduction of the photocurrent response. The prepared PEC biosensor can achieve the sensitive detection of chlorpyrifos with the board detection range varied from 0.001 μg mL−1 to 1.5 μg mL−1 and the detection limit was about 0.07 ng mL−1 (S/N = 3). It is the first time that NCQDs/TiO2 is adopted to construct the PEC biosensor for chlorpyrifos detection. The obtained PEC biosensor can also achieve the detection of chlorpyrifos in the lake water and Chinese cabbage samples, suggesting that the fabricated PEC biosensor had potential application for the detection of OPs in environment and food. A novel visible light driven self-powdered photoelectrochemical (PEC) biosensor was constructed by adopting the NCQDs/TiO2 as the photoactive matrix and AChE as the biological recognition molecule for the sensitive detection of organophosphorus pesticides (OPs) by using chlorpyrifos as the model. [Display omitted] •The photoelectrochemical (PEC) biosensors for the sensitive organophosphorus pesticides detection was constructed.•The photocurrent of the NCQD/TiO2 electrode revealed about 42 times than that of the TiO2/ITO under visible light.•NCQDs endowed with good electrical conductivity and excellent optical performance improve the visible light utilization.•The mechanism of the prepared PEC biosensor was investigated.•The PEC biosensor displayed the receivable applicability for the organophosphorus pesticides detection in