抄録
The sensing of biomolecules is essential for the early detection of diseases. While target molecules and receptors for various diseases have been investigated for medical diagnosis, the detection system is also important. Enzymelinked immunosorbent assay (ELISA) is a current technique with high sensitivity; however, this method is timer–consuming and labor–intensive (need hours to days) because the diffusion of substances to the reaction site inside the well is slow. Thus, a rapid and sensitive detection system is still required for application of point–of–care testing (POCT).
To solve this problem, we developed a new rapid and sensitive biosensing device using the pore space of a porous membrane as the reaction space. Porous membranes have a unique morphology (nano–microscale pores) and a large available surface area, and efficient utilization of the pore space will lead to a promising material for POCT. Although the idea using small pores as the recognition space is also seen in microfluidic devices, the use of membrane pores can achieve further miniaturization of the flow channel. In our membrane–based sensor, receptor molecule is densely immobilized inside the pores by using the plasma graft polymerization technique, which enables uniform grafting in the membrane thickness direction. Also, the detection time required for molecular recognition can be shortened by using solution flow through the membrane pores. This system is demonstrated via antigen (target molecule)–antibody (receptor) system, and it achieves superior signal characteristics to conventional ELISA with a detection time of 35 min. We expect that this new system aids the design of biosensing devices, and could be applied to various diagnostic areas including POCT.
