Microwave-assisted synthesis of highly luminescent AgInS₂/ZnS nanocrystals for dynamic intracellular Cu(ii) detection

Low-toxicity, highly luminescent, and water-soluble AgInS₂/ZnS nanocrystals (NCs) have been synthesized via a microwave-assisted approach. The structure and optical features of the AgInS₂/ZnS NCs were characterized by X-ray diffraction, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet visible absorption spectroscopy and photoluminescence (PL) spectroscopy. The as-synthesized AgInS₂/ZnS NCs exhibited high PL quantum yields (40%) and long PL lifetimes (424.5 ns). Furthermore, the dynamic changes of the intracellular copper(ii) levels in HeLa cells were monitored using the AgInS₂/ZnS NCs as fluorescent probes. The results showed that the AgInS₂/ZnS NCs as promising fluorescent probes can be used in the detection of intracellular copper ions in living cells.