Fig. 4From: N,N-Dimethyl Formamide Regulating Fluorescence of MXene Quantum Dots for the Sensitive Determination of Fe3+a Fluorescence emission spectra of MQDs with the addition of ferric ion; b calibration line between the concentration of Fe3+ and the fluorescence ratio; c the zeta potential of the prepared MQDs; and d UV–Vis absorption spectra of MQDs with and without the addition of Fe3+ionsBack to article page