biostudies-literatureSasan SAcademy of Scientific and Innovative ResearchUniversity of JammuCouncil for Scientific and Industrial Research11114-11125https://www.ebi.ac.uk/biostudies/studies/S-EPMC8991908biostudies-literatureUnknown7(13)Two cyanoimidazopyridine-based sensors (SS1 and SS2) were explored for the colorimetric and fluorometric detection of Fe²⁺, Fe³⁺, and Cu²⁺ ions in the semi-aqueous medium. The "turn-off" fluorescence response of both sensors to these ions was due to the restriction in internal charge transfer. Job's plot and semi-empirical calculations revealed that SS1 and SS2 complexed with Cu²⁺ ions in a 1:1 ratio and Fe^2+/3+ ions in a 2:1 ratio, respectively. The sensors were found to have high binding constant (<i>K</i> _a) values and low detection limit values. FMO analysis using the semi-empirical quantum mechanics method revealed the decrease in energy gap after complexation with metal ions. Sensor-coated filter paper strips were prepared and analyzed, where the color changes in the strips could be utilized for the real-time detection of Fe²⁺, Fe³⁺, and Cu²⁺ ions.ACS omegaFluorescence "Turn-Off" and Colorimetric Sensor for Fe²⁺, Fe³⁺, and Cu²⁺ Ions Based on a 2,5,7-Triarylimidazopyridine Scaffold.PMC8991908OLP0136Gupta AParkesh RSasan SChopra TKapoor KKTsering DfalseFluorescence "Turn-Off" and Colorimetric Sensor for Fe²⁺, Fe³⁺, and Cu²⁺ Ions Based on a 2,5,7-Triarylimidazopyridine Scaffold.Two cyanoimidazopyridine-based sensors (SS1 and SS2) were explored for the colorimetric and fluorometric detection of Fe²⁺, Fe³⁺, and Cu²⁺ ions in the semi-aqueous medium. The "turn-off" fluorescence response of both sensors to these ions was due to the restriction in internal charge transfer. Job's plot and semi-empirical calculations revealed that SS1 and SS2 complexed with Cu²⁺ ions in a 1:1 ratio and Fe^2+/3+ ions in a 2:1 ratio, respectively. The sensors were found to have high binding constant (<i>K</i> _a) values and low detection limit values. FMO analysis using the semi-empirical quantum mechanics method revealed the decrease in energy gap after complexation with metal ions. Sensor-coated filter paper strips were prepared and analyzed, where the color changes in the strips could be utilized for the real-time detection of Fe²⁺, Fe³⁺, and Cu²⁺ ions.2022-01-01T00:00:00Z2022 Apr2025-04-04T12:40:43.353Z2025-04-04T12:40:43.353ZS-EPMC89919083541535310.1021/acsomega.1c07193