A novel fluorescent assay for edaravone with aqueous functional CdSe quantum dots.

Aqueous thiol-capped CdSe QDs with a narrow, symmetric emission were prepared under a low temperature. Based on the fluorescence enhancement of thiol-stabilized CdSe quantum dots (QDs) caused by edaravone, a simple, rapid and specific quantitative method was proposed to the edaravone determination. The concentration dependence of fluorescence intensity followed the binding of edaravone to surface of the thiol-capped CdSe QDs was effectively described by a modified Langmuir-type binding isotherm. Factors affecting the fluorescence detection for edaravone with thiol-stabilized CdSe QDs were studied, such as the effect of pH, reaction time, the concentration of CdSe QDs and so on. Under the optimal conditions, the calibration plot of C/(I-I(0)) with concentration of edaravone was linear in the range of (1.45-17.42) microg/mL (0.008-0.1 micromol/L) with correlation coefficient of 0.998. The limit of detection (LOD) (3sigma/kappa) was 0.15 microg/mL (0.0009 micromol/mL). Possible interaction mechanism was discussed.