Prepared carbon dots from wheat straw for detection of Cu2+ in cells and zebrafish and room temperature phosphorescent anti-counterfeiting

The green synthesis of fluorescent carbon dots from biomass is critical for their sustainable application. Herein, using wheat straw as a single precursor, carbon dots (CDs) were prepared through a one-step carbonization process, and the obtained CDs have intense blue luminescence and excitation-independent photoluminescent behavior. The solution of CDs shows good biocompatibility, and low cytotoxicity successfully used as hopeful bioimaging and biosensing probe for Cu2+ in HepG2 cells and zebrafish. Based on CDs, boron-doped carbon dots with IPA shells (CDs@IPA) can be obtained by doping boron element and isophthalic acid (IPA) coating. CDs@IPA irradiated with different wavelength ultraviolet lamps shows different solid fluorescence, while turning off the ultraviolet lamp can produce green visible room temperature phosphorescence (RTP) to the naked eyes for 5 s. The two kinds of wheat straw-based carbon dots have bifunctional luminescence properties and can be used to detect Cu2+ and serve as RTP anti-counterfeiting signs to ensure information security.

Automated summary

The green synthesis of fluorescent carbon dots from wheat straw as a precursor has been achieved, and these carbon dots exhibit intense blue luminescence. In addition, boron-doped carbon dots with isophthalic acid coating have been prepared, which show visible room temperature phosphorescence under ultraviolet lamp excitation. These wheat straw-based carbon dots have bifunctional luminescence properties, making them suitable for metal ion detection as well as anti-counterfeiting applications.