Design and applications of carbon dots-based ratiometric fluorescent probes: A review

Ratiometric fluorescence (FL) probes can eliminate the background interference and provide more accurate detection results than single emission intensity-based nanoprobes. Recently, carbon dots (CDs)-based ratiometric FL probes have received extensive research attention due to their excellent biocompatibility, water solubility, and multi-emission capabilities. In this review, we firstly summarize the construction strategies of CDs-based ratiometric FL probes, including physical mixing, nanohybrid, and dual-emitting CDs strategies. Additionally, we classify the sensing types of CDs-based ratiometric FL probes into five categories according to the difference in spectral variation caused by analytes: single-response-ON, single-response-OFF, double-responses-ON, double-responses-OFF, and double-responses-Reverse types. Finally, a thorough overview of CDs-based ratiometric FL probe applications in ions, molecules, pH, and temperature sensing is provided. We believe this review can show the latest research progress of CDs-based ratiometric FL sensing fields and provide perspectives on future developments for the construction of CDs-based ratiometric FL probes and their potential applications.

Automated summary

This review provides an overview of carbon dots (CDs)-based ratiometric fluorescence (FL) probes, focusing on their construction strategies and applications in ions, molecules, pH, and temperature sensing. CDs-based ratiometric FL probes have gained extensive research attention due to their excellent biocompatibility, water solubility, and multi-emission capabilities. The probes can eliminate background interference and provide more accurate detection results. The sensing types of CDs-based ratiometric FL probes are classified into five categories based on the difference in spectral variation caused by analytes.