A Novel Copper Ion Fluorescent Probe Based on Tetraphenylimidazole

Copper ions (Cu²⁺) are essential trace elements that play a vital role in maintaining physiological activities, while their homeostasis imbalance is associated with the pathogenesis of various diseases. Therefore, developing a highly selective and sensitive detection method for copper ions (Cu²⁺) is of significant importance. This study successfully synthesized a novel fluorescent probe, tetraphenylimidazole derivative (TPHB), for the specific recognition of copper ions (Cu²⁺). It exhibits excellent optical properties, including fluorescence quenching upon Cu²⁺ binding. The detection limit reaches as low as 0.047 µM, with a binding constant (K) of 3.56 × 10⁴ M^-¹, demonstrating its high sensitivity. Fluorescence calibration curves, mass spectrometry, and ¹H NMR spectroscopy confirmed a 2:1 Cu²⁺ binding ratio for TPHB. It exhibits strong resistance to interference from common ions such as Al³⁺. Furthermore, it was successfully applied in rapid detection test strips, demonstrating excellent detection performance in simulated water samples.