Development of Simple and Effective Dual-Readout Sensor Based on Gold Nanoparticles and Cadmium Telluride Quantum Dots for Cartap Analysis

Abstract

Cartap is among the most popular pesticides that are widely used to boost food production, however, its residues pose a great threat to human health and the environment. We presented simple and effective colorimetric sensor based on aggregation of gold nanoparticles (AuNPs) with appropriate diameter and fluorescent sensor via inner filter effect (IFE) of AuNPs on cadmium telluride quantum dots (CdTe QDs), respectively. Firstly, effect of diameter of AuNPs was investigated and the results indicated that AuNPs with diameter of 13[Formula: see text]nm (AuNPs[Formula: see text] showed better sensitivity toward cartap. Thus, AuNPs[Formula: see text] was chosen for colorimetric and fluorescent cartap assay. On one hand, mercaptoacetic acid (MA) was functionalized on AuNPs[Formula: see text] for the improvement of anti-disturbance ability for discrimination study. A decent linear relationship for cartap was obtained in the range from 1[Formula: see text][Formula: see text]M to 50[Formula: see text][Formula: see text]M with detection limit of 1.32[Formula: see text][Formula: see text]M for colorimetric readout; on the other hand, fluorescent sensor based on AuNPs[Formula: see text] displayed excellent linear relationship with cartap concentration varying from 20[Formula: see text]nM to 100[Formula: see text]nM with low detection limit of 4.02[Formula: see text]nM. And the above-mentioned sensor showed acceptable anti-disturbance ability for cartap discrimination. These results demonstrated that the sensor as-developed would be a great potential candidate for cartap detection in real application.