Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing 100083, China.
Department of Biological and Agricultural Engineering, University of Arkansas, Fayetteville, AR 72701, USA.
Food Chem. 2024 Dec 1;460(Pt 1):140488. doi: 10.1016/j.foodchem.2024.140488. Epub 2024 Jul 22.
Salmonella screening is essential to avoid food poisoning. A simple, fast and sensitive colorimetric biosensor was elaborately developed for Salmonella detection on a microfluidic chip through limiting air chambers for precise air control, switching rotary valves for accurate fluid selection, a convergence-and-divergence passive micromixer and an extrusion-and-suction active micromixer for efficient fluid mixing, and immune gold@platinum palladium nanocatalysts for effective signal amplification. The mixture of bacteria, immune magnetic nanobeads and nanocatalysts was first rapidly mixed to form nanobead-bacteria-nanocatalyst conjugates and magnetically separated for enrichment. After washing with water, the conjugates were used to catalyze colorless substrate and blue product was finally analyzed using ImageJ for quantifying bacterial concentration. The finger-actuated microfluidic chip enabled designated control of designated fluids in designated places towards designated directions by simple press-release operations on designated air chambers without any external power. Under optimal conditions, this sensor could detect Salmonella at 45 CFU/mL in 25 min.
沙门氏菌筛查对于避免食物中毒至关重要。通过限制空气室来精确控制空气、切换旋转阀来准确选择流体、采用汇聚-发散式无源微混合器和挤压-抽吸式主动微混合器来实现高效流体混合，以及利用免疫金@铂钯纳米催化剂实现有效信号放大，我们精心研制了一种用于在微流控芯片上检测沙门氏菌的简单、快速且灵敏的比色生物传感器。首先，将细菌、免疫磁性纳米珠和纳米催化剂的混合物快速混合，形成纳米珠-细菌-纳米催化剂复合物，并通过磁场进行分离富集。用去离子水洗涤后，复合物用于催化无色底物，最后使用 ImageJ 分析蓝色产物，以定量细菌浓度。通过在指定的空气室上进行简单的按压-释放操作，手指驱动的微流控芯片能够实现指定的流体在指定的位置按照指定的方向流动，无需任何外部电源。在最佳条件下，该传感器可以在 25 分钟内检测到 45 CFU/mL 的沙门氏菌。
