Yellow-green fluorescent carbon dots as fluorescent/colorimetric dual-mode probe for the detection of pH value and its application in fluorescent painting

Yellow-green fluorescent carbon dots（Y-G-CDs）was used as a fluorescent/colorimetric dual-mode nanoprobe for the detection of pH value in solution and fluorescent painting. The fluorescent intensity and absorbance of the nanoprobe showed strong pH dependence. The fluorescent intensity at 520 nm and the ratio of absorbance at 438 and 386 nm showed good linear relationships with the pH value，in the ranges of pH 5.9-7.7 and pH 5.9-8.0，respectively. As a fluorescent nanoprobe，Y-G-CDs had good photo stability at pH 5.9，6.8 and 8.0，and good reversibility between pH 5.9 and pH 7.7. The detection of pH value of solution was not affected by other interfering substances. In addition，the Y-G-CDs with excellent fluorescent performance have been successfully applied in fluorescent painting as a fluorescent ink. Under the irradiation of 365 nm UV light，the drawing image emitted bright green fluorescence with clear outline. © 2022, Youke Publishing Co.,Ltd. All rights reserved.