A colorimetric sensor for sensitive and highly selective detection of butyl hydroxyanisole in edible oil based on dual-enzyme-mimic activities of Ag2CO3 nanozymes

Butylated hydroxyanisole (BHA) is a synthetic phenolic antioxidant widely used in edible oils and fat-containing foods. Excessive BHA poses significant risks to human health, thus making rapid and sensitive detection of BHA crucial for health protection. Herein, the Ag 2 CO 3 nanozyme was prepared by the simple precipitation method, which exhibits both laccase-mimic and oxidase-mimic activities. It was found that the oxidase-mimic activity of Ag 2 CO 3 facilitated the conversion of TMB to its blue oxidized form (oxTMB), and subsequent addition of BHA resulted in the formation of a characteristic purple adduct. Additionally, BHA effectively suppressed the laccase-mimic activity of the Ag 2 CO 3 nanozymes. Therefore, a novel colorimetric sensor was constructed using the dual-enzyme-mimic activities as a sensing signal for rapidly detecting BHA in edible oil. The colorimetric sensor achieves limits of detection (LOD) for BHA as low as 1.1 μM in the laccase-mimic channel and 0.08 mM in the oxidase-mimic channel, both of which are substantially lower than the maximum permissible BHA level in edible oils stipulated in Chinese National Food Safety Standard GB 2760. The sensor developed in this work shows great promise for application in the field of edible oil detection.