Selective detection for seven kinds of antibiotics with blue emitting carbon dots and Al3+ ions

In this work, we presented a facile microwave method to prepare blue emitting carbon dots (CDs) using lysine as carbon source and realized the specific detection of seven types of antibiotics by CDs and Al3+ ions via a two-step method. The CDs have good solubility in water and their excitation spectra are exactly coincided with the absorption of some typical antibiotics, which leads to the fluorescence quenching of CDs (OFF state). The inhibition mechanism of fluorescence is induced by the combination of inner filtering effect (IFE) and static quenching effect (SQE). In addition, the quenched fluorescence can be recovered by adding Al3+ ions (On state), and seven types of antibiotics can be distinguished exactly according to the emission peak position and intensity. It not only provides a new and convenient method for the detection of antibiotics, but also provides a new idea for the further application of CDs in optical sensing. (C) 2019 Elsevier B.V. All rights reserved.