Analytical Sciences

Preparation of a Surface-functionalized Power-free PDMS Microchip for MicroRNA Detection Utilizing Electron Beam-induced Graft Polymerization

Ryo ISHIHARA,* Yoshitaka UCHINO,* Kazuo HOSOKAWA,** Mizuo MAEDA,** and Akihiko KIKUCHI*

*Department of Materials Science and Technology, Tokyo University of Science, 6-3-1 Niijuku, Katsushika, Tokyo 125-8585, Japan
** Bioengineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan

We propose an easy microchannel surface functionalization method for a poly(dimethylsiloxane) (PDMS) microchip that utilizes electron beam-induced graft polymerization (EIGP) as a platform for microchip-based biomarker analysis. Unlike other grafting techniques, EIGP enables rapid surface modification of PDMS without initiator immobilization. The grafted microchip is preservable, and can be easily functionalized for versatile applications. In this study, the surface-functionalized power-free microchip (SF-PF microchip) was used for the detection of microRNA (miRNA), which is a biomarker for many serious diseases. The EIGP enables high-density three-dimensional probe DNA immobilization, resulting in rapid and sensitive miRNA detection on the portable SF-PF microchip. The limit of detection was 0.8 pM, the required sample volume was 0.5 μL, and the analysis time was 15 min. The SF-PF microchip will be a versatile platform for microchip-based point-of-care diagnosis.

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