p-Amino benzenesulfonic acid functionalized gold nanoparticles: Synthesis, colorimetric detection of carbaryl and mechanism study by zeta potential assays

Combining the intriguing optical properties with the inherent zeta potential induced instability properties of p-amino benzenesulfonic acid functionalized gold nanoparticles (PABSA-Au NPs), a novel colorimetric detection method for carbaryl was developed. Both the color and zeta-potential of the sensor changed obviously when carbaryl was added, the limit of detection (LOD) was determined to be 0.25 μM (0.05025 mg/L), which is in accord with the maximum contamination level of 0.05 mg/L for carbaryl as defined by the Chinese Environmental Protection Agency. Furthermore, the detection system presents excellent anti-disturbance ability when exposed to a series of interfering ionic/pesticides mixtures and can be applied to the determination of carbaryl in real different water samples such as the Yangtze River sample and East Lake water samples with the LOD as low as 0.25 μM and 0.10 μM, respectively. It is noteworthy that the surface zeta potential measurements are used as a new tool to investigate the aggregation mechanism of the nanoprobes. In addition, our detection system can realize relatively effective removal of carbaryl.