Application of a Gold /Poly(Congo Red) Modified Electrochemical Sensor Toward Fast and Reliable Detection of the Oxazolidinone Fungicide Famoxadone in Vegetables

Abstract

The synthesis and optimization of an electrochemical sensor based on gold nanoparticles (AuNPs)/ conducting poly Congo red dye (poly(CR)) nanocomposite is reported for the detection of the Oxazolidinone fungicide famoxadone (FAM), an environmentally hazardous material. The modification of a glassy carbon electrode (GCE) was performed using cyclic voltammetry (CV) to deposit poly(CR) while AuNPs were deposited using chronoamperometry. Two linear ranges 0.001 – 1 µM (0.37 – 374.40) µg/L and 3 – 100 µM (1.12 – 37.44) mg/L were recorded using AuNPs/poly (Congo Red)/GCE sensor for FAM with limit of detection (LOD) of 0.17 nM (0.06 µg/L) and limit of quantification (LOQ) of 0.48 nM (0.18 µg/L). The tested sensor showed good stability, reproducibility, and repeatability. in addition, sufficient selectivity towards FAM in the presence of other tested pesticides was shown. Finally, the fabricated sensor was applied for the determination of FAM in vegetables and commercial fungicides formulation, with a recovery range 98.9 - 105.4% and RSD 0.70– 4.46%, which represents its efficiency in comparison with previously reported chromatographic methods.

Innovative Molecularly Imprinted Electrochemical Sensor for Selective Nanomolar Detection of the Anti-COVID-19 Medication Molnupiravir

“…For example, gold is a type of nanomaterial that has been widely applied to increase the imprinted site numbers in MIPs and boost the performance of sensors. [66][67][68] So, the main target of this study is to create an artificial recognition element-based voltammetric sensor by electro-polymerizing o-phenylenediamine as a monomer with MLN as a template and a layer of AuNPs to improve selectivity, sensitivity, and measurement window size due to specific MLN recognition cavities being imprinted so as to benefit from the MIP teconology on the sensitivity and selective identification of analytes as result of enhanced surface adsorption and quick binding kinetics between the target analyte and the modified sensor's surface. Finally, the developed sensor was applied for monitoring MLN in capsules and biological fluids (plasma and urine and testing the stability of MLN under different stress conditions.…”