Bio-inspired aptamers decorated gold nanoparticles enable visualized detection of malathion

Abstract

Biosensors always respond to the targets of interest in a specific manner, employing biological or bio-mimic recognition elements such as antibodies and aptamers. Inspired by target recognition in nature, an aptamer-mediated, gold nanoparticle-based sensing approach is developed in this work for effective determination of malathion. The sensing system consists of negatively charged aptamer probes, and polycationic proteins, protamine, as well as exceptional colorimetric nanoprobes, barely gold nanoparticles (AuNPs). Protamine molecules bound to aptamer probes hinder the aggregation of AuNPs, while no such inhibition is maintained when aptamer-specific malathion is introduced into the solution, thus leading to the solution colour change from red to blue observable by the naked eye. The assay is accomplished via a mix-and-measure step within 40 min with a detection limit as low as 1.48 μg/L (3σ/s rule). The assay method also exhibits high selectivity and good applicability for the quantification of malathion in tap water with recovery rates of 98.9%–109.4%. Additionally, the good detection accuracy is also confirmed by the high-performance liquid chromatography method. Therefore, the non-enzymatic, label- and device-free characteristics make it a robust tool for malathion assay in agricultural, environmental, and medical fields.

Detection of Environmentally Harmful Malathion Pesticides Using a Bimetallic Oxide of CuO Nanoparticles Dispersed over a 3D ZnO Nanoflower

“…CuO-based nanomaterials have been used in electrochemical sensors to detect various organic and inorganic molecules and pollutants, for instance, the application of CuO nanoparticles onto multi-walled carbon arrays as glucose sensors [17,18]. Initially, a hybrid nanocomposite including single-walled carbon nanotubes (SWCNTs) and copper-oxide nanowires (CuO NWs) was used to create a novel electrochemical sensor for the detection of organophosphorus pesticides (OPs) [19,20].…”