Preparation and fluorescence detection of nitrogen-doped carbon quantum dots/cotton fiber composites

From the perspective of environmental protection and sustainable development, fluorescent probes have been prepared using inexpensive raw materials for fluorescence detection in wastewater treatment. Nitrogen-doped carbon quantum dots (N-CQDs)/cotton fiber composites were prepared by grafting N-CQDs onto the oxidized cotton fibers using a silane coupling agents. Through a series of characterizations using X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray energy dispersive spectrometry (EDS), it was found that N-CQDs were loaded onto cotton fibers. In the N-CQDs/cotton fiber composite, the fluorescence rate of carbon quantum dots is higher, which is 17.2 %, and the detection limit is 1.21 μM. The optimum conditions for fluorescence detection of azo dye Chrome black T(EBT) with pH 8 and concentration 10 μM were studied. This method for the detection of EBT has advantages such as high sensitivity, simplicity, speed, reusability, and a high potential for application in wastewater detection.