Rapid, in-field speciation of Cr(VI) in aqueous samples using photoluminescent MoS quantum dots and portable fluorimetry with digital image analysis.

This study explores a novel approach for in-field speciation of Cr(VI) in various aqueous samples employing nontoxic, MoS quantum dots (QDs) as a fluorescent probe. The proposed fluorimetric method, compatible with commercial instruments, utilizes a portable custom-built fluorimeter equipped with a multi-wavelength LED array. The method seamlessly incorporates digital image analysis, with fluorescence signals recorded by a smartphone for detection and signal analysis.

Determination of naphazoline hydrochloride in biological and pharmaceutical samples by a quantum dot-assisted chemiluminescence system using response-surface methodology.

A simple and highly sensitive chemiluminescence (CL) method is reported for the determination of naphazoline hydrochloride (NH). It was found that the weak CL from the reaction of luminol and KIO4 in an alkaline medium could be highly amplified by cysteine-capped cadmium telluride quantum dots (QDs) and the enhanced CL was effectively quenched by NH and this finding was utilized as a basis for the determination of NH. The QDs were synthesized in aqueous medium and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis and photoluminescence spectroscopy.