An unusual highly sensitive dual-channel bis(salamo)-like chemical probe for recognizing B4O72-, sensing mechanism, theoretical calculations and practical applications

Abstract

A bis(salamo)-like chemical sensor H₃L ((1E,3E)-2-hydroxy-5-methylisophthalaldehyde O,O -di(3-((((E)-(2-hydroxynaphthalen-1-yl)methylene)amino)oxy)propyl) dioxime) was constructed. H₃L is capable of recognizing B₄O₇^2- in H₂O/DMF (1:9, v/v) solution by both fluorescent and colorimetric channels, bright green fluorescence was turned on when B₄O₇^2- was added to H₃L and changed from colorless to yellow in natural light. The detection limit was 3.21 × 10^-8 M. The identification has good anti-interfering ability, quickly responsive time (5 S) and broad pH detecting range (pH = 5-12). The mechanism of action was determined by ¹H NMR titration, infrared spectrometry, HRMS spectra and further elucidated by theory calculations. The fluorescence imaging of bean sprouts and spiked recovery assays of actual water samples demonstrated the practical use of sensor H₃L for the detection of B₄O₇^2-, which is expected to have applications for the detection of B₄O₇^2- in plants and the environment.

Keywords: Bis(salamo)-like sensor; Dual-channel identification; Mechanism; Tetraborate ion; Theory calculation.