High fluorescent nitrogen − doped carbon dots derived from Sanghuangporus lonicericola for detecting tetracyclines in aquaculture water and rat serum samples

Tetracyclines (TCs) are a kind of broad − spectrum and effective antibiotics that have been widely used in veterinary and human medicine, which may pose serious risk to human health if they are accumulated in human body. The fluorescence method using nanomaterials as probes has been gradually used for the detection of TCs because of its simple operation, high sensitivity and recognition ability. Herein, a novel nitrogen doped carbon dots (N − CDs) derived from Sanghuangporus lonicericola was synthesized by hydrothermal method. The N − CDs exhibited bright blue fluorescence, high quantum yield (QY) of 60.99 %, and excellent photostability, which was employed as a fluorescent probe for selective detection of TCs, including oxytetracycline (OXY), doxycycline (DOX), tetracycline (TCY) and minocycline (MNO). The fluorescence intensity of the N − CDs decreased linearly with the increasing concentration of OXY, DOX, TCY and MNO, and their concentrations were in the range of 0.6 – 73.3 μM, 0 – 95.2 μM, 6.5 – 72.3 μM and 10 – 52.6 μM, respectively. As for practical application, the as − prepared N − CDs could not only be effectively applied for determination of TCs in aquaculture water and rat serum samples with low relative standard deviation (RSD) and good recoveries, but also track the concentration change of TCs in rats blood model over time. Towards the fluorescence detection mechanism, the results of UV–vis absorption spectra and fluorescence lifetimes proved that the fluorescent quenching of N − CDs occurred from internal filtration effect (IFE) in the presence of TCs. This work provides guidance for the development of new TCs sensors based on fluorescent nanomaterials, and has a good application prospect in the quality control of agriculture, food and pharmaceutical production processes.