Fin-like CdSeS Nanoplatelets for Pesticide Sensing

Pesticide residues in farm products create human health hazards. Hence, sensors that detect their existence are advantageous to address this critical problem. In this research contribution, fin-like CdSeS nanoplatelets were synthesized from solution by adjusting the selenium-to-sulfur molar ratio. Structural and photophysical properties were characterized via XPS, XRD, UV absorption, and fluorescence emission. CdSeS nanoplatelets exhibit a regular fin-like structure when the molar ratio of selenium-to-sulfur is 1:1. Fluorescence emission from these nanoplatelets occurs at two distinct wavelengths, characteristic of quantum dots. CdSeS fin-like nanoplatelets generate red-shifted fluorescence to 530 nm, which is useful to detect the popular organophosphorus pesticide dimethoate effectively at concentrations that range from 10–5 to 10–7 mol/L. Upon increasing dimethoate concentrations in solution, fluorescence intensity of CdSeS nanoplatelets decreases. Hence, direct sensing of dimethoate is feasible. Another important significance of this work is the use of low-toxicity and recyclable cadmium acetate instead of cancer-causing and nonrecyclable cadmium oxide, which will be helpful to reduce environmental pollution.