One-touch-activated blood multidiagnostic system using a minimally invasive hollow microneedle integrated with a paper-based sensor.

The development of real-time innocuous blood diagnosis has been a long-standing goal in healthcare; an improved, miniature, all-in-one point-of-care testing (POCT) system with low cost and simplified operation is highly desired. Here, we present a one-touch-activated blood multidiagnostic system (OBMS) involving the synergistic integration of a hollow microneedle and paper-based sensor, providing a number of unique characteristics for simplifying the design of microsystems and enhancing user performance. In this OBMS, all functions of blood collection, serum separation, and detection were sequentially automated in one single device that only required one-touch activation by finger-power without additional operations. For the first time, we successfully demonstrated the operation of this system in vivo in glucose and cholesterol diagnosis, showing a great possibility for human clinical application and commercialization. Additionally, this novel system offers a new approach for the use of microneedles and paper sensors as promising intelligent elements in future real-time healthcare monitoring devices.

Tear-off patterning: a simple method for patterning nitrocellulose membranes to improve the performance of point-of-care diagnostic biosensors.

This article describes a new method, referred to as "tear-off patterning," for patterning nitrocellulose (NC) membranes in order to fabricate NC-based point-of-care (POC) diagnostic devices. Paper-based microfluidic sensors usually employ hydrophobic barrier coatings such as paraffin wax on either paper or membranes. Herein, complex patterns were fabricated by stamping the target area with dimethyl sulfoxide before tearing off the stamped area. Fluid flow and morphological analyses were performed in order to characterize the patterned membranes. Furthermore, the myoglobin and creatine kinase-MB levels in human serum were measured simultaneously using a dual-fluidic-channel-patterned NC membrane in order to confirm the usefulness of the patterning method for fabricating POC biosensors. The proposed method for patterning NC membranes offers clear advantages, such as the ability to fabricate complex designs and patterns without a hydrophobic barrier after protein immobilization in a laboratory and in a simple, low-cost manner. We believe that this method can be used to develop various POC diagnostic biosensors at the research and development stage and can help improve the performance and features of POC diagnostic devices.