An ultrasensitive colorimetric and fluorescent “turn-on” chemosensor based on Schiff base for the detection of Cu2+ in the aqueous medium

• Published in: Environmental monitoring and assessment 2023-06, Vol.195 (6), p.633-633, Article 633
• Main Authors: Khan, Sikandar, Muhammad, Mian, Kamran, Abdul Waheed, Al-Saidi, Hamed M., Alharthi, Salman S., Algethami, Jari S.
• Format: Article
• Language: English
• Subjects: Aluminum; Analytical methods; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Calcium ions; Carbon dioxide; Chemical sensors; Chemoreceptors; Cobalt; Colorimetry; Copper; Detection; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental science; Fluorescence; Fluorescence spectroscopy; Fourier transforms; Geometry; Imines; Infrared spectroscopy; Investigations; Ions; Lead; Magnesium; Monitoring/Environmental Analysis; NMR; Nuclear magnetic resonance; Synthesis; Titration; Zinc
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-023-11260-3

We designed and synthesized a fluorescent “turn-on” and colorimetric chemosensor ((E)-1-((p-tolylimino)methyl)naphthalen-2-ol) SB . The structure of the synthesized chemosensor was investigated by 1 H NMR, FT-IR, and fluorescence spectroscopy, and its sensing properties were studied toward Mn 2+ , Cu 2+ , Pb 2+ , Cd 2+ , Na + , Ni 2+ , Al 3+ , K + , Ag + , Zn 2+ , Co 2+ , Cr 3+ , Hg 2+ , Ca 2+ , and Mg 2+ . SB showed an excellent colorimetric (yellow to yellowish brown) in MeOH and fluorescence “turn-on” sensing response to Cu 2+ in MeOH/Water (10/90, v/v) media. The sensing mechanism of SB toward Cu 2+ was investigated by FT-IR, 1 H NMR titration, DFT studies, and Job’s plot analysis. The detection limit was calculated to be very low 0.0025 µg mL −1 (0.0025 ppm). Furthermore, the test strip containing SB also showed excellent selectivity and sensitivity toward Cu 2+ in a solution medium and when supported on a solid medium.