An efficient tetrahydroquinazolin-2-amine derivative-grafted cellulose fluorescent probe for detection of Cu²⁺ and...

Cu²⁺ and Zn²⁺ play crucial roles in many physiological processes, and their disorder will cause harm to human health. An efficient difunctional fluorescent probe CMC-GE-PQA for simultaneous detection of Cu²⁺ and Zn²⁺ was synthesized based on carboxymethyl cellulose. The probe CMC-GE-PQA exhibited a moderate blue fluorescence color. Interestingly, this probe showed a distinct fluorescence enhancement response toward Zn²⁺, while it displayed a significant fluorescence quenching response toward Cu²⁺. The detection limits of CMC-GE-PQA for Cu²⁺ and Zn²⁺ were calculated as low as 5.0 × 10^-8 M and 1.0 × 10^-7 M, respectively. The detection mechanisms of CMC-GE-PQA for Cu²⁺ and Zn²⁺ were fully verified by Job's plot, X-ray photoelectron spectroscopy analysis. The probe CMC-GE-PQA was applied to determine the trace amounts of Cu²⁺ and Zn²⁺ in environmental water samples. In addition, the probe CMC-GE-PQA-based fluorescent film and hydrogel were manufactured to achieve the portable detection of Cu²⁺ and Zn²⁺.