A Disposable Organophosphorus Pesticides Enzyme Biosensor Based on Magnetic Composite Nano-Particles Modified Screen Printed Carbon Electrode

Sensors

Ning Gan¹  Xin Yang¹  Donghua Xie²  Yuanzhao Wu¹ 

[1] The State Key Laboratory Base of Novel Functional Materials and Preparation Science, Faculty of Material Science and Chemical Engineering of Ningbo University, Ningbo, 315211, China; E-Mails:;The Technical Center of Ningbo Entry-Exit Inspection and Quarantine Bureau, Ningbo, 315200, China; E-Mail:

关键词: Fe₃O₄/Au composite nanoparticles;    carbon nanotubes;    nano-ZrO₂;    acetyl-cholinesterase;    organophosphorus pesticides;    prussian blue;    screen-printed carbon electrodes;    enzyme biosensor;   

DOI  :  10.3390/s100100625

来源: mdpi

【 摘 要 】

A disposable organophosphorus pesticides (OPs) enzyme biosensor based on magnetic composite nanoparticle-modified screen printed carbon electrodes (SPCE) has been developed. Firstly, an acetylcholinesterase (AChE)-coated Fe₃O₄/Au (GMP) magnetic nanoparticulate (GMP-AChE) was synthesized. Then, GMP-AChE was absorbed on the surface of a SPCE modified by carbon nanotubes (CNTs)/nano-ZrO₂/prussian blue (PB)/Nafion (Nf) composite membrane by an external magnetic field. Thus, the biosensor (SPCE│CNTs/ZrO₂/PB/Nf│GMP-AChE) for OPs was fabricated. The surface of the biosensor was characterized by scanning electron micrography (SEM) and X-ray fluorescence spectrometery (XRFS) and its electrochemical properties were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The degree of inhibition (A%) of the AChE by OPs was determined by measuring the reduction current of the PB generated by the AChE-catalyzed hydrolysis of acetylthiocholine (ATCh). In pH = 7.5 KNO₃ solution, the A was related linearly to the concentration of dimethoate in the range from 1.0 × 10⁻³–10 ng·mL⁻¹ with a detection limit of 5.6 × 10⁻⁴ ng·mL⁻¹. The recovery rates in Chinese cabbage exhibited a range of 88%–105%. The results were consistent with the standard gas chromatography (GC) method. Compared with other enzyme biosensors the proposed biosensor exhibited high sensitivity, good selectivity with disposable, low consumption of sample. In particular its surface can be easily renewed by removal of the magnet. The convenient, fast and sensitive voltammetric measurement opens new opportunities for OPs analysis.

【 授权许可】

CC BY   
©2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.