Synthesis of molybdenum oxide quantum dots with better dispersity and bio-imaging ability by reduction method

A reduction method was proposed to synthesize better dispersed molybdenum oxide quantum dots (MoO x QDs) with stable fluorescence properties by using molybdenum disulfide (MoS 2 ) and hydrogen peroxide (H 2 O 2 ) as precursor and oxidant, and using ethanol as reducing agent and surfactant of oleylamine as modified agent. The morphology of the as-prepared MoO x QDs with average size of 1.96 nm were observed, calculated and analyzed from TEM and AFM detections. Excitation-dependent photoluminescence emission of MoO x QDs could be obtained and MoO x QDs exhibited blue fluorescence under UV light irradiation. Factors that influenced the syntheses of MoO x QDs were discussed, and the highest value of fluorescence intensity was exhibited with the adding of 5 mL oleylamine and the reaction time of 24 h. The cell imaging behaviors, the physiological stabilities and in vitro cytotoxicity testing of MoO x QDs were further discussed with HeLa cells as model. And the results showed that it might be a promising biomedical material as high quality fluorescent probes for bio-imaging.