Pesticide analytical screening system (PASS): A novel electrochemical system for multiplex screening of glyphosate and chlorpyrifos in high-fat and low-fat food matrices

Abstract

On-field detection of pesticide residue in complex-food matrices is a challenge when it comes to analytical detection involving multistep extraction and purification. In this study, we test the feasibility of an electrochemical portable device for detection of spiked pesticides Glyphosate (Glyp) and Chlorpyrifos (Chlp) in low-fat and high-fat food matrix. The immunoassay based two-plex sensing platform was fabricated using respective antibody glyphosate on one side and chlorpyrifos antibody on other side. The sensor response was tested using non-faradaic electrochemical impedance spectroscopy (EIS), which showed a linear response in Glyp/Chlp concentrations from 0.3 ng/mL to 243 ng/mL with limit of detection 1 ng/mL for low fat and 1 ng/mL to 243 ng/mL with LOD 1 ng/mL for high-fat matrix respectively. The laboratory-based benchtop data was then compared with portable device for feasibility of application as portable device. Such electrochemical portable sensing approach can be a future commercial field testing tool.

Keywords: Cucumber; Electrochemical impedance spectroscopy (EIS); Electrochemical sensors; Glyphosate; Label-free; Pesticide; Pesticides in food; Protein powder.