Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
KAIST Institute for Health Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Korea.
Sensors (Basel). 2020 Apr 16;20(8):2267. doi: 10.3390/s20082267.
Although immunomagnetic separation is a useful sample pretreatment method that can be used to separate target pathogens from a raw sample, it is challenging to remove unbound free magnetic nanoparticles (MNPs) for colorimetric detection of target pathogens. Here, size-based filtration was exploited for the rapid on-site detection of pathogens separated by immunomagnetic separation in order to remove unbound free MNPs using a finger-powered microfluidic device. A membrane filter and an absorbent pad were integrated into the device and a mixture of unbound free MNPs and MNP-bound () O157:H7 was dispensed over the membrane filter by pressing and releasing the pressure chamber. A colorimetric signal was generated by MNP-bound O157:H7 while unbound free MNPs were washed out by the absorbent. Furthermore, the colorimetric signals can be amplified using a gold enhancer solution when gold-coated MNPs were used instead of MNPs. As a result, 10 CFU/mL O157:H7 could be detected by the enhanced colorimetric signal on a proposed device.
虽然免疫磁分离是一种有用的样品预处理方法，可用于从原始样品中分离目标病原体，但去除未结合的游离磁性纳米颗粒 (MNP) 对于目标病原体的比色检测仍然具有挑战性。在这里，基于尺寸的过滤被用于快速现场检测通过免疫磁分离分离的病原体，以便使用手指驱动的微流控装置去除未结合的游离 MNP。将膜过滤器和吸收垫集成到装置中，并且通过按压和释放压力室将未结合的游离 MNPs 和 MNP 结合的 () O157:H7 的混合物分配在膜过滤器上。通过 MNP 结合的 O157:H7 产生比色信号，而未结合的游离 MNPs 则被吸收垫洗出。此外，当使用金涂覆的 MNP 代替 MNP 时，可以使用金增强剂溶液来放大比色信号。因此，通过在提出的装置上的增强比色信号可以检测到 10 CFU/mL 的 O157:H7。
