Department of Chemistry, University of Kansas, Lawrence, KS 66045, United States.
Lab Chip. 2013 Nov 7;13(21):4190-7. doi: 10.1039/c3lc50783a.
Quantitative detection of low abundance proteins is of significant interest for biological and clinical applications. Here we report an integrated microfluidic solid-phase ELISA platform for rapid and ultrasensitive detection of proteins with a wide dynamic range. Compared to the existing microfluidic devices that perform affinity capture and enzyme-based optical detection in a constant channel volume, the key novelty of our design is two-fold. First, our system integrates a microwell-patterned assay chamber that can be pneumatically actuated to significantly reduce the volume of chemifluorescent reaction, markedly improving the sensitivity and speed of ELISA. Second, monolithic integration of on-chip pumps and the actuatable assay chamber allow programmable fluid delivery and effective mixing for rapid and sensitive immunoassays. Ultrasensitive microfluidic ELISA was demonstrated for insulin-like growth factor 1 receptor (IGF-1R) across at least five orders of magnitude with an extremely low detection limit of 21.8 aM. The microwell-based solid-phase ELISA strategy provides an expandable platform for developing the next-generation microfluidic immunoassay systems that integrate and automate digital and analog measurements to further improve the sensitivity, dynamic ranges, and reproducibility of proteomic analysis.
定量检测低丰度蛋白质对于生物和临床应用具有重要意义。在这里，我们报告了一种集成的微流控固相 ELISA 平台，用于快速和超灵敏地检测具有宽动态范围的蛋白质。与现有的在恒定通道体积中进行亲和捕获和基于酶的光学检测的微流控设备相比，我们设计的关键新颖之处有两点。首先，我们的系统集成了微井图案化的检测室，可通过气动驱动来显著减少化学荧光反应的体积，从而显著提高 ELISA 的灵敏度和速度。其次，芯片上泵和可驱动检测室的单片集成允许可编程的流体输送和有效的混合，以实现快速和灵敏的免疫分析。我们演示了胰岛素样生长因子 1 受体（IGF-1R）的超灵敏微流控 ELISA，其检测范围至少跨越五个数量级，检测限极低，为 21.8 aM。基于微井的固相 ELISA 策略为开发下一代微流控免疫分析系统提供了一个可扩展的平台，该系统集成和自动化数字和模拟测量，以进一步提高蛋白质组学分析的灵敏度、动态范围和重现性。
