Surface recognition strategy via ascorbic acid-triggered decomposition of boron nitride-loaded cobalt oxyhydroxide nanosheets

Highlights: • Boron nitride was assembled together with cobalt oxyhydroxide. • The recovery of boron nitride emission caused the determination of ascorbic acid. • Ascorbic acid decomposed the CoOOH and colorimetric sensing was realized. -- Abstract: As for the accurate determination of analytes, most of chemical probes suffer from poor selectivity and data fluctuation. Sensor systems via colorimetric and fluorometric modes have caused considerable interests since the two ways are free from employment of special instrumentation and complicated techniques. A new type of cobalt oxyhydroxide (CoOOH) nanosheet has been developed and boron nitride is incorporated. Such nanoplatform can oxidize o-phenylenediamine (OPD) to 2,3-diaminophenazine (OxOPD) with emission change. In the presence of ascorbic acid, CoOOH can be reduced to Co²⁺ ions and the generation of OxOPD has been suppressed. Therefore, the fluorescent signal of boron nitride has been recovered and ratiometric determination for ascorbic acid can be realized (detection limit: 1.07 μM; linear range: 0.05–80 μM). In addition, colorless 3,3′,5,5′-tetramethylbenzidine (TMB) can be transformed into oxidized form-TMBox with blue color and the sensitivity can reach as low as 120 nM. Current study will not only provide a typical case of colorimetric and fluorometric sensing for quantitative analysis of ascorbic acid, but also promote a new molecular design concept in practical field.