Combinatorial experimental and DFT theoretical evaluation of a nano novel thio-dicarboxaldehyde based Schiff base supported on a thin polymer film as a chemosensor for Pb2+ detection

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2018-06, Vol.360, p.152-165
• Main Authors: Karachi, Nima, Azadi, Omid, Razavi, Razieh, Tahvili, Arash, Parsaee, Zohreh
• Format: Article
• Language: English
• Subjects: Chemosensor; Lead ion; Schiff base; Spin coating; Ultrasound
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2018.04.039

[Display omitted] •First ultrasound-spin coating assisted fabrication of dual OFF-ON chemosensor for detection and removal of Pb (II) ions.•The explanation of the chemosensor behavior based on the colorimetric assay and fluorescence assay.•The confirmation of the sensing results using DFT approach. A novel high selective and sensitive fluorescent-colorimetric sensor have been developed for the determination of Pb2+ ions based on an ultrasound-assisted nano thieno[2,3-b]thiophene-2,5-dicarboxaldehyde-based Schiff base (H2L). A silica-based portable probe was fabricated via spin coating of H2L on a glass slide with diameter of 64 nm which has been applied in real sample successfully. The probe has been exploited as a dual chemosensor to detection lead ions in aqueous media with a detection limit of 6.78 μg/L and 7.38 μg/L respectively and dynamic concentration range of 0.6 × 10−8 to 4.12 × 10−5 mol L−1. Based on the Job plot analysis, 1:1 stoichiometric ratio between H2L and Pb2+ has been established. The removal percentage range of lead ions has been obtained 96–99.6% with a response time of 80 s. Furthermore, DFT calculated molecular orbital, energy gap, MPA, MEP and ESP of the optimized structure of chemosensor confirmed the sensing results.