A Microwell-Based Impedance Sensor in Microneedle Shape for Multiplexing Cytokine Detection

Monitoring cytokine profiles plays a crucial role in predictive medicine and early disease diagnosis, as well as enables basic research in many biological fields. Although single cytokine measurement can be very useful, simultaneous assessment of multiple biomolecular signatures can more fully illuminate complex biological function. To this end, multiplexing technologies for simultaneous assessment of multiple cytokines on a single measurement device have recently attracted significant interest. Despite the promise of these techniques, many still require specialized instrumentation or do not function in real-time, impeding their clinical adoption as point-of-care systems. Microfabrication can be exploited to create impedance-based cytokine sensors that can supply realtime assessment information; further, microfabrication can lead to device form factors suitable for in vivo operation. We present microfabricated needle-shaped microwell impedance sensors for rapid, label-free multiplexing detection of multiple cytokines. The sensor utilizes a microwell array configuration in which multiple microwell sensors are distributed along the needle shank. Multiplexed detection of multiple cytokines in vitro using these devices is demonstrated.