A Dual-Mode Optical Sensing Strategy for Rapid Detection of D-Penicillamine in Pharmaceutical Formulations

Accurate, rapid, and quantitative detection of D-penicillamine (D-PA) in pharmaceutical formulations is imperative for drug quality and clinical medication guidance. Various colorimetric and fluorescent assays have been constructed for D-PA based on nanomaterials. However, the reliable and rapid detection of D-PA in pharmaceutical formulations remains a challenge because these methods suffer from shortcomings such as time-consuming procedures, poor uniformity, and complicated nanomaterial preparation. In this work, an effective and facile homogeneous dual-mode optical sensing strategy was established based on the strong complexation between D-PA and Cu2+ and catalyzed the oxidation of O-phenylenediamine. This platform displayed a sensitive response to D-PA from 5 to 100 µmol/L, with a detection limits of 0.54 µmol/L (fluorescence) and 0.76 µmol/L (colorimetry). As expected, the method was successfully applied to the determination of D-PA in pharmaceutical formulations with satisfactory results. Overall, this developed strategy provides a facile and rapid dual-mode optical platform for D-PA and has great potential in D-PA-related pharmaceutical quality control.