Fluorescence sensor based on d-penicillamine capped cadmium sulfide quantum dots for the detection of cysteamine

A fluorescence sensor for selective detection of cysteamine derived from D-penicillamine capped cadmium sulfide quantum dots (DPA-CdS QDs) is proposed. The DPA-CdS QDs were successfully synthesized via a simple method in a one-pot reaction. The morphology of DPA-CdS QDs was characterized by transmission electron microscopy (TEM) revealing spherical shapes with an average size of 3.2±0.5 nm. In the presence of cysteamine, the fluorescence intensity of the DPA-CdS QDs was enhanced proportionally with increasing cysteamine concentration. The proposed fluorescence sensor can be used to detect cysteamine in a wide range of working concentrations up to 10 μM and with a limit of detection of 0.07 μM. Furthermore, this sensor can be efficiently used for the detection of cysteamine in real urine samples with high accuracy.