Highly Sensitive and Selective Fluorescence Probe for 2,4-Dinitrophenylhydrazine Detection in Wastewater Using Water-Soluble CdTe QDs.

A simple, cheap, sensitive and selective probe for determination of DNPH in wastewater using thioglycolic acid (TGA)-coated CdTe QDs (TGA-QDs) as fluorescence probe has been established, and the properties of CdTe QDs were characterized by TEM, FT-IR, DLS, XRD and zeta potentials. CdTe QDs fluorescence is highly efficiently quenched after adding DNPH on account of electron transfer effect, and the fluorescence quenching behavior of CdTe QDs interaction with DNPH is static quenching process. A good linear relationship is observed between the relative fluorescence intensity (F0 /F) and 0.06-10 ng mL-1 of DNPH. As compared with some of reported methods, LOD of this method for analysis of DNPH (0.23 ng mL-1 ) is the lowest. Masking agents of DDTC and NH4 OH can eliminate the interference of Cu2+ , Ag+ and Hg2+ . Hence, DNPH can be selectively and accurately detected and the established method was successfully used for detecting DNPH in wastewater with acceptable recovery of 90.6-102%.