Ultrasensitive electrochemical aptasensors based on trimetallic AuPt-Ru nanoparticles decorated RGO with disposable and low-cost goldleaf electrode for aflatoxin B1 quantification in agricultural products

Abstract

Due to the significant increase in cases of liver cirrhosis and hepatocellular carcinoma associated with the agricultural products consumption contaminated with Aflatoxin B1 (AFB1), there is an urgent need for rapid AFB1 detection methods. Herein, we propose using waxberry-like heterostructure AuPt-Ru nanoparticles supported by RGO (AuPt-Ru/RGO) embedded goldleaf as a disposable and low-cost electrode (GLEAuPt-Ru/RGO) for electrochemical aptasensor detection of AFB1. The trimetallic AuPt-Ru nanocomposite was synthesized through the ultrasonic-driven chemical reduction method. The AuPt-Ru was integrated with RGO to accelerate the electron transfer and increase the specific immobilizing surface area of the thiol-5′-terminated modified aptamer (aptamer) to target AFB1 on GLE. The electrochemical aptasensor GLEAuPt-Ru/RGO shows a highly selective response for AFB1 through specific hydrogen bonding and π-π stacking interactions. The linearity of differential pulse voltammetry (DPV) measurements for AFB1 was 0.3–30.0 pg mL−1 (R2 = 0.9972) with a detection limit (LOD) and a quantification limit (LOQ) of 9 × 10−3 pg mL−1 and 3.1 × 10−2 pg mL−1, respectively. The developed aptamer-based GLEAuPt-Ru/RGO performed effectively in actual samples, with recoveries ranging from 94.6 % to 107.9 % in agricultural products including dried red chili, garlic, peanuts, pepper, and Thai jasmine rice. The fabricated aptamer-based GLE-decorated AuPt-Ru/RGO exhibited excellent electrochemical behavior similar to that of a modified commercial electrode, which has great potential application prospects for detecting AFB1 in agricultural products.