Key Laboratory of Agricultural Information Acquisition Technology, Ministry of Agriculture and Rural Affairs, China Agricultural University, Beijing, China.
College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510642, China.
Biosens Bioelectron. 2022 Dec 15;218:114765. doi: 10.1016/j.bios.2022.114765. Epub 2022 Oct 4.
In-field screening of pathogenic bacteria is important for preventing food poisoning. Here, a portable pipette-adapted biosensor using magnetic grid separation and nanocatalyst signal amplification was elaboratively developed for rapid detection of Salmonella typhimurium. A common pipette was innovatively adapted with multiple functions to complete the whole bacterial detection procedure, including mixing, separation, catalysis, washing, detection, analysis and display. The target bacteria were effectively captured by the immune magnetic nanobeads and labeled with immune gold@platinum nanocatalysts through pipette-blowing mixing to form the nanobeads-bacteria-nanocatalyst complexes, which were separated against the magnetic grid separation tip under the magnetic field. The pressure change resulting from oxygen production due to mimicking catalysis of hydrogen peroxide by these nanocatalysts on the complexes was quantified through measuring the moving duration of the conductive liquid in the pipette for bacteria determination. Under optimal conditions, this biosensor could detect target bacteria in 90 min with low detection limit of 180 CFU/mL. This pipette-adapted biosensor is affordable, sensitive, specific, user-friendly, rapid and robust, equipment-free and deliverable to end-users (ASSURED), and has the potential for in-field testing of foodborne pathogens to ensure food safety, especially in resource-constrained areas.
现场筛选致病菌对于预防食物中毒非常重要。在这里，我们精心开发了一种基于磁性网格分离和纳米催化剂信号放大的便携式移液管适配生物传感器，用于快速检测鼠伤寒沙门氏菌。我们创新性地利用普通移液管的多种功能完成了整个细菌检测过程，包括混合、分离、催化、洗涤、检测、分析和显示。目标细菌通过免疫磁性纳米珠被有效捕获，并通过移液管吹气混合与免疫金@铂纳米催化剂标记，形成纳米珠-细菌-纳米催化剂复合物，在磁场下用磁性网格分离尖端将其分离。通过测量移液管中导电液体的移动时间来定量检测复合物中纳米催化剂模拟催化过氧化氢产生氧气所导致的压力变化，从而实现对细菌的定量检测。在最佳条件下，该生物传感器可在 90 分钟内检测到 180 CFU/mL 的低检测限。这种移液管适配生物传感器价格实惠、灵敏、特异、易于使用、快速且稳健，无需设备且可交付给最终用户（ASSURED），具有在现场测试食源性病原体以确保食品安全的潜力，特别是在资源有限的地区。
