An Acylhydrazone-Based Fluorescent Sensor for Sequential Recognition of Al3+ and H2PO4. MATERIALS (BASEL, SWITZERLAND) 2021;14:6392. [PMID: 34771920 PMCID: PMC8585233 DOI: 10.3390/ma14216392]

A novel acylhydrazone-based fluorescent sensor NATB was designed and synthesized for consecutive sensing of Al3+ and H2PO4-. NATB displayed fluorometric sensing to Al3+ and could sequentially detect H2PO4- by fluorescence quenching. The limits of detection for Al3+ and H2PO4- were determined to be 0.83 and 1.7 μM, respectively. The binding ratios of NATB to Al3+ and NATB-Al3+ to H2PO4- were found to be 1:1. The sequential recognition of Al3+ and H2PO4- by NATB could be repeated consecutively. In addition, the practicality of NATB was confirmed with the application of test strips. The sensing mechanisms of Al3+ and H2PO4- by NATB were investigated through fluorescence and UV-Visible spectroscopy, Job plot, ESI-MS, 1H NMR titration, and DFT calculations.

Hydrogen-Bonded Colorimetric and Fluorescence Chemosensor for Fluoride Anion With High Selectivity and Sensitivity: A Review

In recent years, the wide application of fluoride materials has grown rapidly, therefore excessive discharge in the surrounding environment, especially in drinking water and organic effluent, has become a potential hazard to humans, and has even resulted in fluorosis disease. The development of a highly effective and convenient method to recognize fluoride anions in surrounding environments seems necessary and urgent. Among which, the development of a colorimetric and fluorescence fluoride chemosensor with obvious color changing allowing for naked-eye detection with high sensitivity and selectivity is more interesting and challenging. In this minireview, current novel colorimetric and fluorescence chemosensors for fluoride anions by hydrogen-bond interaction are introduced, including obvious color changing by naked-eye detection, high sensitivity and selectivity, non-pollution and fluoride extraction ability, aqueous detection, and other additional functions. Finally, the perspective of the fluoride chemosensor design concept and potential evolution trends are pointed out.

Selective anions mediated fluorescence "turn-on", aggregation induced emission (AIE) and lysozyme targeting properties of pyrene-naphthalene sulphonyl conjugate

We have designed and synthesized a novel pyrene-naphthalene sulphonyl conjugate, 1-((1Z)-(4-((Z)-4-(pyrene-1-yl)methyleneamino)phenylsulfonyl)phenylimino)methyl)naphthalene-2-ol (PSN) through a facile two-step reactions. It was characterized by various spectral techniques. Fluorescence spectral studies showed that compound PSN featured fluorescence enhancement upon increasing the water content in THF. This can be attributed to the phenomena of aggregated induced emission (AIE), which is confirmed by SEM and AFM studies, due to the restriction of CHN isomerization of PSN. The anion sensing of PSN was examined with various anions. Among these anions, H₂PO₄^- and F^- ions were selectively sensing with a low detection limit of 3.52 × 10^-7 M and 7.23 × 10^-7 M, respectively, and an obvious color change from yellow to orange was observed by the naked eye. The mechanism of sensing involved the formation of hydrogen bonding interaction between O-H group of PSN and H₂PO₄^-/ F^- ions. The binding of PSN with LYZ was also examined by docking studies, which shows that H-bonding and hydrophobic interactions play crucial roles for the interaction of LYZ toward PSN.