Nanozymatic degradation and simultaneous colorimetric detection of tetracycline.

Tetracycline (TC) is a broad-spectrum antibiotic that can enter and accumulate in the human body via the food chain. Even in small concentrations, TC can cause several malignant health effects. We developed a system to simultaneously degrade the presence of TC in food matrices using titanium carbide MXene (FL-TiCT). The FL-TiCT exhibited biocatalytic property that activates hydrogen peroxide (HO) molecules in 3, 3', 5, 5'-tetramethylbenzidine (TMB environment. During the FL-TiCT reaction, the catalytic products released turn the color of the HO/TMB system bluish-green. However, when TC is present, the bluish-green color does not appear. Via quadrupole time-of-flight mass spectrometry, we found that the TC is degraded by FL-TiCT / HO in preference to HO/TMB redox reaction, which intervenes in the color change. Hence, we developed a colorimetric assay to detect TC with a LOD of 615.38 nM and proposed two TC degradation pathways that facilitate the highly sensitive colorimetric bioassay.