Manganese-Doped Zinc Sulfide Quantum Dots for Determination of Bisphenol A by Room Temperature Phosphorescence

Abstract

Manganese-doped ZnS quantum dots were synthesized through a facile process in aqueous solution using L-cysteine as a surface modifying agent. The quantum dots were characterized by transmission electron microscopy and X-ray diffraction spectroscopy, and had a favorable room-temperature phosphorescence property, with a longer emission time and a narrower emission profile than fluorescence. The phosphorescence was quenched by bisphenol A. Based on these findings, a room temperature phosphorescence quenching method was developed for the sensitive and selective detection of bisphenol A. Under the optimized conditions, the detection limit was 0.2 ng · mL⁻¹, and the relative standard deviation was 1.14% (C = 10 ng · mL⁻¹, n = 11). The proposed method was successfully applied to plastic products with satisfactory results. The recovery of the method was in the range of 96% to 106%.

Keywords:

• Bisphenol A (BPA)
• Mn-doped ZnS quantum dots
• Room-temperature phosphorescence