ELECTROCHEMICAL BIOSENSOR BASED ON GOLD NANOSTRUCTURES AND CYSTEINE-DIPHENYLALANINE PEPTIDE FOR THE DETECTION OF CARBAMATE-BASED PESTICIDES

Within the strategies applied to increase agricultural productivity, chemical compounds capable of eliminating pests have been widely adopted across various crops. However, using these compounds raises food safety, occupational health, and environmental impact issues. Thus, the development of new technologies for the efficient detection of pesticides in different matrices, especially environmental ones, has been a constant focus of research and improvement. In this context, biosensors emerge as an attractive alternative for analyte quantification, considering their advantages over traditional methods, which often involve high costs for necessary materials and specialized labor. This study presents the development of an amperometric electrochemical biosensor based on the immobilization of acetylcholinesterase enzyme on gold nanoparticles synthesized from the cysteine-diphenylalanine peptide (CFF), which acts as both reducer and stabilizer, using the hydrothermal method. Due to its unique characteristics, the CFF peptide provided excellent morphological control to the gold nanostructures (R_H at about 16 nm) and high uniformity in size distribution (PDI of 0.322). Carbamate detection was performed using square wave voltammetry, with results indicating the high sensitivity of the biosensor. The calibration curve covered the concentration range of 10⁻⁹ mol L⁻¹, with a determination coefficient (R²) of 0.99, and the detection limit was calculated at 0.94 x 10⁻⁹ mol L⁻¹. The inclusion of CFF and its unique properties resulted in an efficient device for carbamate detection, presenting a fast and economical alternative to traditional methods for environmental and agricultural monitoring.