Water‐Soluble One‐Pot Green Synthesis of Collagen Stabilized Copper Nanoclusters for Selective Fluorescent Turn‐Off Detection of Iron(III)

ABSTRACT The affordable and readily available 3d metal copper with collagen as a stabilizing agent demonstrates the effective production of fluorescent copper nanoclusters. A facile one‐pot green approach has been developed to obtain collagen‐stabilized fluorescent copper nanoclusters (Collagen‐CuNCs). The fluorescent Collagen‐CuNCs were characterized by different methods, such as HR‐TEM, FT‐IR, XPS, UV–Vis, and fluorescence spectroscopy. The metal ions selectivity of Collagen‐CuNCs was examined in an aqueous medium by adding Ca 2+ , Hg 2+ , Cd 2+ , Pb 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ , Fe 3+ , Cr 3+ , Al 3+ , and Fe 2+ ions. Ferric ions selectively quenched the fluorescence emission of Collagen‐CuNCs (λ em = 480 nm), among other tested metal ions. The fluorescence quenching mechanism was investigated using Stern‐Volmer analysis and time‐resolved fluorescence. With a nanomolar detection limit of 0.14 nM, the developed nanoprobe Collagen‐CuNCs was employed to quantify Fe 3+ ions in spiked blood serum.