A nanosensor based on p-nitrophenyldiazenylphenyloxadiazole (NDPO) capped CdSe quantum dots (QDs) was developed for Cd2+ ions in aqueous solutions. The nanosensor exhibited a high selectivity for cadmium ions and showed linear correlation with Cd2+ ions concentration in the range of 0.05–1.0 mmol/L. The prepared NDPO capped CdSe QDs were characterized by TEM, SEM, EDX, and FTIR techniques.
