One minute synthesis of green fluorescent copper nanocluster: The preparation of smartphone aided paper-based kit for on-site monitoring of nanomolar level mercury and sulfide ions in environmental samples.

We wish to report, a minute synthesis of green fluorescent copper nanocluster by simple sonication. 1-Thio-β-d-glucose was used as a capping ligand to synthesis copper nanocluster (TG-CuNCs). The TG-CuNCs exhibit the emission maximum at 430 nm. The synthesized TG-CuNCs was well characterized by UV-vis, fluorescent, XRD, HR-TEM and FT-IR techniques. After the addition of Hg or S into TG-CuNCs, the fluorescence was quenched. Based on the quenching of fluorescence, we have calculated the detection limit 1.7 nM and 1.02 nM for Hg and S, respectively. Finally, we have applied TG-CuNCs for the detection of Hg and S in tap, river, pond water. Importantly, the smartphone aided paper-based kit was developed for on-site monitoring of Hg and S ions. To the best of our knowledge, this is the first report for the one-minute synthesis of TG-CuNCs and the preparation of smartphone aided paper-based kit for on-site monitoring of Hg and S ions. Further, it is anticipated that this synthesis of TG-CuNCs and smartphone aided paper-based kit for Hg and S will be useful materials in the filled with the biosensor, material science and nanotechnology.