Rational Building of Nonblinking Carbon Dots via Charged State Recovery

Carbon dots (CDs), as emerging luminescent nanomaterials, possess excellent but complex properties, and thus, they have attracted immense attention for their applications. Further practical application of CDs has been hindered by their limited photostability and photoluminescence intermittency. In this study, we demonstrated that an antioxidant (Trolox) can dramatically enhance the photostability and minimize the photoblinking of CDs without affecting their native spectral characteristics. Significant photoluminescence enhancement and stabilization were observed with the addition of Trolox in ensemble level. Meanwhile, strikingly stable emissions from individual CDs have been observed in the presence of Trolox in single-particle-level experiments. Our observations revealed that the charged state of CDs can be effectively recovered to a neutral state by Trolox via electron transfer. These results prove that the combination of antioxidants and CDs is a powerful means to improve their fluorescence robustness, which is crucial for applications that demand long-lived, nonblinking emission.