Fig. 3. (A) The emission spectra of CuNCs under 300 nm excitation with the increasing concentration of the hemin. Inset: the calibration plot of (F0 − F) versus hemin concentration, where F and F0 respectively represented the fluorescence intensity of CuNCs with and without hemin. (B) Fluorescence excitation and emission spectra of the CuNCs, and UV-vis absorption spectrum of hemin. (C) Selectivity of the “turn off” sensor for hemin. The concentration of hemin and other substance are 1.0 μM. The error bars are the standard deviation of three measurements.
