Photoinduced electron transfer between quantum dots and pralidoxime: an efficient sensing strategy

Abstract

Photoinduced electron transfer (PET)-mediated fluorescence quenching of CdTe/CdS quantum dots in the presence of pralidoxime (PAM) was extensively studied using various techniques including fluorescence spectroscopy, UV-Vis spectroscopy and voltammetry. As a result of this study, a highly sensitive fluorescence sensing strategy was developed for quantifying PAM, enabling its concentration to be determined at sub-micromolar levels. Under optimized conditions, this PET-mediated turn-off sensor can be used for determining the concentration of PAM in the concentration range 5.00 × 10⁻⁸ M to 4.00 × 10⁻⁶ M. The limit of detection (LOD) and limit of quantification (LOQ) here were calculated to be 1.48 × 10⁻⁸ M and 4.92 × 10⁻⁸ M, respectively. The practical utility of the developed sensor was assessed in artificial urine samples and commercially available PAM injection formulation.