Fluorescein-derived carbon dots with chitin-targeting for ultrafast and superstable fluorescent imaging of fungi

Abstract Fluorescence microscopy based on fluorochrome has been rapidly developed as the candidate for morphological identification of pathogenic fungi over recent years, offering superior rapidity and efficacy traditional culture methods. However, intrinsic quenching properties fluorescein limit clinical application fluorescence imaging. Herein, we report a nano-strategy by converting commercial dye, fluorescent brightener-33 (FB-33), into carbon dots (FB-CDs) through one-pot hydrothermal method. FB-CDs exhibit chitin-targeting capacity allowing selective recognition ultrafast imaging within 30 s. The quantum yield is 51.6% which 8.6-fold higher than that FB-33. Moreover, also display superstable signals under continuous intense light irradiation 2 h long-term storage more months. significantly improved photobleaching resistance meets prolonged observation quantitative analysis microbial samples. This work offers novel nanoconversion strategy dyes point-of-care testing organisms.