WITHDRAWN: One-pot hydrothermal synthesis of a carbon dot-based pH fluorescent probe

In this work, a new fluorescent and pH-dependent carbon dots fluorescent probe was first developed using 4,4′-bipyridine and citric acid as precursors using a one-pot hydrothermal method. The prepared carbon dots had relatively high fluorescence intensity and quantum yield(4.03%) as well as good water solubility. The results showed that the probe was excited at 390 nm and had a good linearity of fluorescence intensity between pH 1.6-3.6 and pH 4.0-6.0. The fluorescent probe has a large pH detection range and is highly sensitive, with small changes in pH causing changes in the fluorescence intensity of the carbon dot fluorescent probe.