Dual emission ratiometric fluorescence probe based on N-doped carbon dots and coumarin derivatives for determination of moxifloxacin and copper ion

Background

Residues of moxifloxacin (MFX) and copper ions (Cu²⁺) can have detrimental health effects on humans. Thus, it is essential to develop a sensitive method for the detection of MFX and Cu²⁺. Fluorescence analysis is a potent technique, offering simplicity, speed, and efficiency. However, analytical results from single-emission fluorescence methods can be affected by environmental factors, probe inhomogeneity, and light-source intensity. Therefore, there is a need to design a novel dual-emission ratiometric fluorescence probe for the determination of MFX and Cu²⁺ to address these challenges and enhance the accuracy and sensitivity of the measurements.

Results

A novel dual emission ratiometric-based fluorescence probe (B/G probe) was constructed by N-doped carbon dots and coumarin derivatives. The B/G probe exhibited two fluorescence emission peaks at 442 nm and 513 nm when excited at 336 nm. The inner-filter effect played a significant role in the quenching characteristics of MFX. Additionally, Cu²⁺ ions were found to have a strong affinity for MFX. Consequently, this fluorescence probe was developed to detect MFX initially and subsequently Cu²⁺ ions. The detection limit (DL) was 17.5 nM and 32.5 nM for MFX and Cu²⁺ ions, respectively. The B/G probe had better selectivity and anti-interference capability. Satisfactory recovery rate indicated that the B/G prob had good accuracy for detection of MFX and Cu²⁺ ions.

Significance

This study represents the inaugural application of N-doped carbon dots and coumarin derivatives to construct a novel dual emission ratiometric-based fluorescence probe, demonstrating a marked advancement in innovation. This approach has significantly enhanced the sensitivity for the determination of MFX and Cu²⁺ ions. Compared with fluorescence probe of single signal, this method provides an effective strategy for detection MFX and Cu²⁺ with good accuracy, good selectivity, rapid detection and lower DL.