Synthesis of fluorescent molybdenum nanoclusters at ambient temperature and their application in biological imaging

We introduce for first time a facile protocol for the rapid synthesis of a molybdenum nanoclusters (MoNCs) at room temperature using thiolated dithiothreitol (DTT) as capping agents. The initial fluorescence from the MoNCs is observed in 30 min and further intensified in 48 h. The mean diameter of nanoclusters was found to be 1.5 nm with -77 mV zeta potential. The nanoclusters have good stability in all tested pH ranges, especially between pH 7 and 10. This property makes the nanomaterial to be ideal for many types of possible biological/biomedicine applications such as drug delivery or biological imaging. The quantum yield of thiolated MoNCs was calculated to be 59% which is higher than the noble metal nanoclusters reported earlier. The mechanism of formation of MoNCs was investigated using the UV-Vis spectroscopy and cyclic voltammetry. Owing to these characteristics, MoNCs were used for imaging of HaCaT and A549 cancer cells. The current approach on novel synthesis of MoNCs is found to be a superior alternative to conventional/popular MoS₂ based on the method of synthesis, particle size, and fluorescence quantum yield. The current approach on the MoNCs has created a new platform for future biomedicine applications.