A benzimidazole-appended double-armed salamo type fluorescence and colorimetric bifunctional sensor for identification of MnO 4 - and its applications in actual water samples.

The symmetrically double-armed salamo type fluorescent sensor BMS, incorporating benzimidazole units, was designed and synthesized. Showcasing remarkable specificity and responsiveness to MnO ₄ ^- within a DMSO:H ₂ O (V/V = 9:1, pH = 7.2) Tris-HCl buffer medium, it enabled dual-channel detection of MnO ₄ ^- through fluorescent and colorimetric changes. Critical experimental parameters, including detection and quantification thresholds (LOD and LOQ) along with binding affinity constants (K _a ), were calculated using the Origin software. A rational interaction mechanism between BMS and MnO ₄ ^- was deduced, based on fluorescence titration, Electrospray Ionization Mass Spectrometry (ESI-MS), Ultraviolet-Visible Spectroscopy (UV-Vis), Infrared Spectroscopy (IR), Stern-Volmer plots, and Density Functional Theory (DFT) computations. Additionally, the sensor BMS was applied to monitor MnO ₄ ^- in real water samples. Advancing its practical utility, BMS was fabricated into test strips for the selective detecting of MnO ₄ ^- .
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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