Two kinds of biomass-derived carbon dots with one-step synthesis for Fe3+ and tetracyclines detection

In this study, we developed an eco-friendly approach by utilizing industrial hemps as the carbon source to synthesize two kinds of CDs by one-pot hydrothermal method. We observed that the excitation wavelength showed dependence on CDs concentration in small CDs (S-CDs), not in big CDs (B-CDs). Further study showed that the B-CDs can be utilized for detection Fe3+ with the detection limit as low as 0.47 μmol L−1. Instead, our S-CDs could be specifically identified tetracycline antibiotics (TC, CTC, OTC) with the detection limits as 0.0330 μmol L−1, 0.27 μmol L−1 and 0.28 μmol L−1, respectively. In addition, we have successfully applied their application in actual sample (bottled drinking water and facial mask) to detect Fe3+ and TC, indicating their practicality. Overall, we have demonstrated that B-CDs and S-CDs detected Fe3+ and tetracycline antibiotics as powerful sensors and their potential applications in food and cosmetics detection of Fe3+ and TC.