Determination of rifampicin based on fluorescence quenching of GSH capped CdTe/ZnS QDs

Aqueous glutathione (GSH)-capped CdTe / ZnS QDs with the diameter of 3–4   nm were synthesized. The fluorescence of CdTe / ZnS QDs at 577   nm was quenched in the presence of rifampicin (Rfp), with excitation wavelength at 350   nm. The mechanism of the interaction of CdTe / ZnS QDs with Rfp was investigated. Under the optimal conditions, the calibration plot of ln( F 0 /F ) was linear in the range 0.83–56   μg   mL −1 with concentration of Rfp, and the detection limit was 0.25   μg   mL −1 . The proposed method was successfully applied to the determination of Rfp in its commercial capsules, and satisfactory results were obtained. The recovery of the method was in the range 98.6–103.2%.