Luminescent Methane Sensor Based on Energy Transfer from ZnS:Mn2+ Quantum Dots to Analyte Molecule

Abstract

Manganese-doped zinc sulfide quantum dots were synthesized by chemical precipitation in an aqueous solution in the presence of glutathione as the capping agent. Obtained samples show dual emission band with maximums at 2.11 eV (Mn²⁺) and about 3.1 eV (intrinsic defects of ZnS QDs). Under exposure to methane in the concentration range from 100 to 2000 ppm the ZnS:Mn²⁺ emission spectrum is changed significantly. It was shown, the luminescent sensor response occurs due to photoinduced electron transfer from QDs to methane molecule resulting in QD luminescence quenching and luminescence lifetime decreasing.