Fluorescent N-doped carbon quantum dots: A selective detection of Fe3+ and understanding its mechanism

Carbon quantum dots (CQDs) based sensor has been built many times. Optical properties, such as optical absorption, have been neglected for too long. Here, we have reported the luminescence of blue-emitting nitrogen-doped carbon quantum dots (N-CQDs) with average particle size 3–6 nm, synthesized via a simple hydrothermal method, which give intense blue emission under 340 nm excitation wavelengths. As the fluorescence of N-CQDs can be efficiently quenched by Fe3+, the N-CQDs can be constructed as a sensor system for Fe3+ with good sensitivity and selectivity. Effective detection and quantification of Fe3+ at as little as 0.07 µM and 0.22 µM is achieved.