Facile synthesis of MoS2 quantum dots as fluorescent probes for sensing of hydroquinone and bioimaging

Abstract

Recently, transition metal dichalcogenide quantum dots have attracted widespread attention among researchers as fluorescent materials. In this work, a facile bottom–up route is proposed to synthesize water-soluble molybdenum disulfide quantum dots (MoS₂ QDs) by using sodium molybdate and cysteine as precursors. The as-prepared spherical MoS₂ QDs with an average size of 3.5 nm exhibit intense PL emission, whose quantum yield (QY) is 6.5% (cal.). In particular, the as-synthesized MoS₂ QDs show highly sensitive and selective detection of H₂Q. The lowest limit of detection can reach 0.3 μM in water, far lower than the estimated wastewater discharge limit of the United States Environmental Protection Agency (EPA) (0.5 mg L⁻¹). What is more, the as-prepared MoS₂ QDs exhibited applicability in cell imaging with lower cytotoxicity. Therefore, the as-prepared MoS₂ QDs show potential applications in environmental monitoring, bioanalysis, disease diagnosis and treatment, etc.