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

[Display omitted] • The probe H 3 L was synthesized with a simple and easily accessible preparation. • H 3 L identifies B 4 O 7 2- by dual fluorescence and colorimetric channels. • The identification possesses high selectivity, fast response and low detection limit. • Good results were obtained in both bean sprout imaging and actual water sample testing. A bis(salamo)-like chemical sensor H 3 L ((1 E ,3 E)-2-hydroxy-5-methylisophthalaldehyde O , O -di(3-((((E)-(2-hydroxynaphthalen-1-yl)methylene)amino)oxy)propyl) dioxime) was constructed. H 3 L is capable of recognizing B 4 O 7 2- in H 2 O/DMF (1:9, v/v) solution by both fluorescent and colorimetric channels, bright green fluorescence was turned on when B 4 O 7 2- was added to H 3 L 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 H 3 L for the detection of B 4 O 7 2−, which is expected to have applications for the detection of B 4 O 7 2− in plants and the environment. [ABSTRACT FROM AUTHOR]