Electrochemiluminescence aptasensor based on 3D flower-like ZnONPs catalysis for the detection of diazinon in vegetables

Abstract

Within this work, an electrochemiluminescence (ECL) aptasensor was constructed for the sensitive detection of diazinon. Primarily, AuNPs not only provided a platform for luminol fixation due to their favorable bioactivity and conductivity, but they facilitated the improvement of ECL signals. Furthermore, three-dimensional (3D) flower-like ZnONPs were obtained by hydrothermal synthesis, which could be an efficacious catalyst for the luminol-hydrogen peroxide (luminol-H2O2) system, whereby the ECL signal of the sensor could be amplified. Given the large specific surface area of 3D flower-like ZnONPs, modification of positive charges on their surface could well immobilized the electronegative aptamer chains on the electrode surface, and when diazinon (DZN) was added, the aptamer combined with DZN to form a complex to hinder the ECL intensity, and the detection of DZN was achieved by the change of ECL signal intensity. After evaluated the experimental parameters, the detection limit of DZN was 0.0109 nM (S/N = 3), and the linear range was 0.0328–3.28 × 104 nM. The proposed ECL aptasensor had comparatively satisfactory detection limits, which provided a reasonable reference for other contaminant residues detection.