A fluorescence turn-off chemosensor based on N-doped carbon quantum dots for detection of Fe3+ in aqueous solution

In this study, new carbon nanomaterial N-doped carbon dots (NCDs) were obtained via a one-step hydrothermal method using isoleucine and citric acid as carbon precursors. TEM results showed that the NCD diameters were not uniform but distributed in the 6–15   nm range, with an average value of 10   nm. The maximum emission wavelength of the obtained NCDs was 415   nm with an excitation wavelength of 370   nm. Under optimal conditions, the nanoparticle can be used as sensors and exhibited a ‘turn-off’ fluorescence response to Fe 3+ , with a good linear relationship of ( F / F 0 ) versus Fe 3+ over the concentration range of 0–20   μmol/L.