Department of Mechanical Engineering, York University, Toronto, ON M3J 1P3, Canada.
Sixth Wave Innovations Inc., Halifax, NS B4A 0H3, Canada.
Biosensors (Basel). 2023 Oct 20;13(10):943. doi: 10.3390/bios13100943.
The rapid, inexpensive, and on-site detection of bacterial contaminants using highly sensitive and specific microfluidic sensors is attracting substantial attention in water quality monitoring applications. Cell-imprinted polymers (CIPs) have emerged as robust, cost-effective, and versatile recognition materials with selective binding sites for capturing whole bacteria. However, electrochemical transduction of the binding event to a measurable signal within a microfluidic device to develop easy-to-use, compact, portable, durable, and affordable sensors remains a challenge. For this paper, we employed CIP-functionalized microwires (CIP-MWs) with an affinity towards and integrated them into a low-cost microfluidic sensor to measure the conductometric transduction of CIP-bacteria binding events. The sensor comprised two CIP-MWs suspended perpendicularly to a PDMS microchannel. The inter-wire electrical resistance of the microchannel was measured before, during, and after exposure of CIP-MWs to bacteria. A decline in the inter-wire resistance of the sensor after 30 min of incubation with bacteria was detected. Resistance change normalization and the subsequent analysis of the sensor's dose-response curve between 0 to 10 CFU/mL bacteria revealed the limits of detection and quantification of 2.1 × 10 CFU/mL and 7.3 × 10 CFU/mL, respectively. The dynamic range of the sensor was 10 to 10 CFU/mL where the bacteria counts were statistically distinguishable from each other. A linear fit in this range resulted in a sensitivity of 7.35 μS per CFU/mL. Experiments using competing or cells showed specificity of the sensor towards the imprinted cells. The reported CIP-MW-based conductometric microfluidic sensor can provide a cost-effective, durable, portable, and real-time solution for the detection of pathogens in water.
使用高度灵敏和特异的微流控传感器快速、廉价、现场检测细菌污染物，这在水质监测应用中引起了极大的关注。细胞印迹聚合物（CIP）作为一种强大、经济高效且多功能的识别材料，具有用于捕获整个细菌的选择性结合位点，已经崭露头角。然而，将结合事件电化学转化为微流控装置内可测量的信号，以开发易于使用、紧凑、便携、耐用且价格合理的传感器仍然是一个挑战。在本文中，我们采用了对 具有亲和力的 CIP 功能化的 microwires（CIP-MWs），并将其集成到低成本微流控传感器中，以测量 CIP-细菌结合事件的电导转换。该传感器由两个垂直悬挂在 PDMS 微通道上的 CIP-MWs 组成。在 CIP-MWs 暴露于细菌之前、期间和之后，测量微通道的线间电阻。在与细菌孵育 30 分钟后，检测到传感器的线间电阻下降。通过对传感器在 0 至 10 CFU/mL 细菌之间的剂量-反应曲线进行归一化和后续分析，检测到检测限和定量限分别为 2.1×10 CFU/mL 和 7.3×10 CFU/mL。传感器的动态范围为 10 至 10 CFU/mL，其中细菌计数彼此之间可统计区分。在该范围内进行线性拟合，得到的灵敏度为 7.35 μS/每 CFU/mL。使用竞争的 或 细胞进行的实验表明，该传感器对印迹的 细胞具有特异性。所报道的基于 CIP-MW 的电导微流控传感器可以为水中病原体的检测提供一种经济高效、耐用、便携和实时的解决方案。
