Abstract:
A low-cost, handheld centrifugal microfluidic system for multiplexed visual detection based on recombinase polymerase amplification (RPA) was developed. A concise centrifugal microfluidic chip featuring four reaction units was developed to run multiplexed RPA amplification in parallel. Additionally, a significantly shrunk-size and cost-effective handheld companion device was developed, incorporating heating, optical, rotation, and sensing modules, to perform multiplexed amplification and visual detection. After one-time sample loading, the metered sample was equally distributed into four separate reactors with high-speed centrifugation. Non-contact heating was adopted for isothermal amplification. A tiny DC motor on top of the chip was used to drive steel beads inside reactors for active mixing. Another small DC motor, which was controlled by an elaborate locking strategy based on magnetic sensing, was adopted for centrifugation and positioning. Visual fluorescence detection was optimized from different sides, including material, surface properties, excitation light, and optical filters. With fluorescence intensity-based visual detection, the detection results could be directly observed through the eyes or with a smartphone. As a proof of concept, the handheld device could detect multiple targets, e.g., different genes of African swine fever virus (ASFV) with the comparable LOD (limit of detection) of 75 copies/test compared to the tube-based RPA.
摘要:
低成本,开发了基于重组酶聚合酶扩增(RPA)的手持式离心微流控系统,用于多路视觉检测。开发了具有四个反应单元的简洁离心微流控芯片,以并行进行多路RPA扩增。此外,开发了一种尺寸明显缩小且具有成本效益的手持配套设备,结合加热,光学,旋转,和传感模块,进行多路扩增和视觉检测。一次性样品加载后,将计量样品等量分配到四个单独的反应器中,并进行高速离心。等温扩增采用非接触加热。芯片顶部的微型直流电动机用于驱动反应器内的钢珠进行主动混合。另一个小型直流电机,这是通过基于磁传感的精心锁定策略控制的,采用离心和定位。视觉荧光检测从不同方面进行了优化,包括材料,表面属性,激发光,和光学滤波器。具有基于荧光强度的视觉检测,检测结果可以通过眼睛或智能手机直接观察。作为概念的证明,手持设备可以检测到多个目标,例如,与基于试管的RPA相比,非洲猪瘟病毒(ASFV)的不同基因具有75个拷贝/测试的可比LOD(检测限)。