Construction of hydrogen bond mediated nitrogen doped carbon quantum dot fluorescent probe and its application in trace detection of ibuprofen in water

Abstract

To address the residual pollution of ibuprofen in aquatic environments, this study developed a fluorescent probe based on nitrogen doped carbon quantum dots (NCQDs) as the core material, which can achieve ultra sensitive detection. By optimizing hydrothermal synthesis conditions, NCQDs with uniform particle size (1-4nm) and surface-rich hydroxyl/amino groups were successfully synthesized. FT-IR confirmed their graphitic carbon core structure and surface functional groups. Experiments revealed that ibuprofen formed hydrogen bonds between its carboxylic acid groups and the hydroxyl/amino groups on NCQDs, passivating defect states and suppressing non-radiative recombination, thereby significantly enhancing fluorescence intensity. A linear response was observed within the range of 0.001-0.01mg/L (R2=0.992), the detection limit is 0.14μg/L. This probe offers an efficient and convenient method for trace-level ibuprofen detection in water environments.