This study introduces a simple colorimetric method for detecting acrylamide, which relies on modulating the oxidase-like activity of MnO2 nanoflowers using a hollow double-stranded DNA (dsDNA) structure. The MnO2 nanoflowers used in this study exhibited a uniform three-dimensional structure with a high specific surface area, mesoporous structure, and uniform elemental distribution of manganese and oxygen, which enhance aptamer binding and sensor performance. When acrylamide is present, it specifically binds to the aptamer, destabilizing the hollow dsDNA and leading to the release of the complementary strands. These strands anchor onto the MnO2 nanoflower surface and enhances its oxidase-like activity. As a result, the catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) is accelerated, which results in a visible color shift from light to dark blue. The developed aptasensor exhibited a linear detection range from 0.1 to 100 nmol/L, with a detection limit of 0.026 nmol/L. The aptasensor demonstrated high selectivity and specificity for acrylamide, even in the presence of interfering compounds. Acrylamide was also successfully quantified in real samples, including roasted nuts and potato chips. Due to its sensitivity, selectivity, and ease of use, this aptasensor offers strong potential for on-site, and naked-eye acrylamide detection in food safety monitoring.

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