G-Quadruplex DNAzyme-Based Biocatalysis Combined with an Intelligent Electromagnetic-Actuated Microfluidic Chip for Tetracycline Detection

作者：Li Wang, Wanwan Wang, Shumin Zhang, Jie Wei, Qingmin Chen, Tianhui Jiao, Anhui Lin, Quansheng Chen, Xiaomei Chen · 发表于：Journal of Agricultural and Food Chemistry · 年份：2024 · DOI：10.1021/acs.jafc.4c09976 · 被引用次数：10 · 研究领域：Advanced biosensing and bioanalysis techniques、Biosensors and Analytical Detection、Carbon and Quantum Dots Applications

In this study, we present an intelligent electromagnetic-actuated microfluidic chip integrated with a G-quadruplex DNAzyme-based biocatalysis platform for rapid and sensitive tetracycline (TC) detection. In this sensing system, TC significantly quenches fluorescent magnetic carbon dots (M-CDs) via the internal filtration effect and dynamic quenching (the excitation and emission wavelength at 350 and 440 nm, respectively). Then, the G-quadruplex on the M-CDs-Aptamer is exposed and bound with hemin to form hemin-G-quadruplex DNAzyme, catalyzing the conversion of 3,3′,5,5′-tetramethylbenzidine to produce blue color. This enables the fluorescence/colorimetric detection of TC. Importantly, an automatic electromagnet-integrated microfluidic chip was designed to control the shuttling of magnetic materials in each function slot according to a programmed sequence. Under the optimal conditions, the detection limits of TC for fluorescence and colorimetric methods were 11 and 43 μmol/L, respectively. The detection results for tilapia ( Oreochromis nilotica ) were comparable to those of traditional high-performance liquid chromatography. This platform offers excellent performance for TC determination and potential for portable, intelligent detection of trace pollutants in food and the environment.