Cupric oxide nanosheet as an oxidase mimic for fluorescent detection of acetone by a 3D-printed portable device.

ABSTRACT

A cupric oxide (CuO) nanosheet-based chemical fluorescence sensor was developed to realize the detection of acetone in aqueous solutions. CuO is an oxidase mimic and can catalyze the oxidation of o-phenylenediamine (OPD) to form 2,3-diaminophenazine (oxOPD). Interestingly, acetone was found to possess the scavenging ability for superoxide anions generated in the CuO-catalyzed oxidation system, hence weakening the OPD oxidation and leading to a reduction in the fluorescence intensity of the catalyzing system at 574 nm under excitation at 425 nm. Based on this property of acetone, a fluorescent sensor was constructed to detect acetone. The sensor exhibits a linear range of 1.35 to 2 × 105 µmol L-1 and a detection limit of 1.08 µmol L-1. Additionally, a smartphone-free portable device was constructed to realize on-the-spot and rapid detection of acetone in cauliflower, mineral water, tap water, and lake water samples. The recoveries by the portable device are 93.2 to 108% for actual samples, with relative standard deviations of less than 4.3%, indicating a potential application prospect of the device in on-site detection.