Synthesis and applications of a fluorescent cyan 2-aryl benzimidazole for environmental sensing, luminescent ink, and coating technologies

Abstract

An efficient luminescence sensor, specifically 2-([1,1′-biphenyl]-4-yl)-1H-benzo[d]imidazole (BBI), has been synthesized through a one-pot green synthesis methodology to detect picric acid (PA) via turn-off quench, demonstrating superior performance relative to numerous nitro aromatic compounds. The compound was characterized using various spectroscopic techniques, in addition to absorption and fluorescence emission studies, to ascertain the sensitivity and selectivity of the probe. The sensor exhibits a limit of detection (LOD) of approximately 1.22 × 10⁻⁷ M and a quenching constant of 1.67 × 10⁵ M⁻¹, as determined by fluorescence measurements. The underlying mechanism of the sensing process was elucidated through both experimental and theoretical analyses. To augment its practical applicability, the sensor was formulated into luminescent ink and gel-based systems for various applications. Additionally, real-world detection capabilities were established by developing solid-contact mode paper strips and glass plate-based detection methods, facilitating the analysis of real-life samples such as soil and water.