Screening of biologically important Zn2+ by a chemosensor with fluorescent turn on-off mechanism

A Schiff-based AIE fluorescent probe for Zn2+ detection and its application as "fluorescence paper-based indicator"

A Schiff-based aggregation induced emission (AIE) fluorescent probe with excited intramolecular proton transfer (ESIPT) mechanism was synthesized by grafting 2-hydrazinobenzothiazole onto 2,6-diformyl-4-methylphenol. The probe recognizes Zn²⁺ selectively and sensitively, accompanied by a significant fluorescence emission increasement change from light yellow-green to strong green. Additionally, a stabilization time of at least 30 min was kept in the recognition process. Besides, a linear relationship was observed between the concentration of Zn²⁺ and the fluorescence intensity at 525 nm (0.05-10 µM). And thus, the probe can detect Zn²⁺ quantitatively in aqueous solution with a low detection limit of 1.9 × 10^-8 M. Based on the AIE property and the selective recognition of Zn²⁺, SCH was strategically loaded on the filter paper to develop a novel paper-based indicator for on-site and high-efficiency detection of Zn²⁺. The results showed that the paper-based indicator could be conveniently applied to the visual inspection of Zn²⁺ as expected and SCH in the paper-based indicators fortunately exhibited a better stability. Furthermore, our comprehensive application evaluations have confirmed that SCH was capable of detecting Zn²⁺ in real water samples and imaging Zn²⁺ in living cells roundly.

A new diformyl phenol based chemosensor selectively detects Zn2+ and Co2+ in the nanomolar range in 100% aqueous medium and HCT live cells

A new diformyl phenol based chemosensor that can sense Zn2+ and Co2+ in the nanomolar range in 100% aqueous solution and in HCT cells was explored.

Fluorescent ZnII Chemosensor Mediated by a 1,8-Naphthyridine Derivative and It's Photophysical Properties

One of the greatest challenges in using fluorescent chemosensors for highly selective and sensitive transition-metal ions is finding an efficient and simple method for its synthesis. In this study, a highly efficient fluorescence chemosensor for ZnII was developed from N-Boc-L-proline modified 1,8-naphthyridine. The fluorescence intensity of the chemosensor was increased significantly only in the presence of ZnII ion which provided a perceived color change for rapid visual sensing, while other metal ions showed fluorescence quenching or little changes. It was worth noting that the chemosensor L distinguished ZnII from CdII commonly having similar properties. The solvent effect and possible bonding mode for fluorescence enhancement have been also discussed. Results of this study indicated that the Boc-group in l-proline significantly improved the sensitivity and selectivity for ZnII detection performance, as confirmed by comparison experiments and time dependent-density functional theory (TD-DFT) calculations.