title: Printed two-dimensional photonic crystals for single-step label-free biosensing of insulin under wet conditions.
abstract: Two-dimensional photonic crystals (2D-PCs) fabricated on a cyclo-olefin polymer (COP) film using a printable photonics technology based on nano-imprint lithography (NIL) were used for label-free biosensing of insulin under wet conditions. In general, 2D-PC-based biosensing involves a complicated dry-up procedure after biosensing reactions on the 2D-PCs to obtain a high sensitivity through the large difference in refractive index. Therefore, it can be difficult to achieve simple operation involving single-step analysis. Performance of the biosensing under wet conditions would simplify the operational procedure. For label-free biosensing of insulin under wet conditions, the Fresnel reflection intensity change was used instead of the wavelength shift, which is the commonly used sensing signal. By detecting changes in refractive index caused by specific interactions between the antigen and antibody as the Fresnel reflection intensity changes, physiologically important concentrations of insulin could be detected, even under wet conditions. These results suggest that low-cost printed 2D-PCs offer great potential for single-step label-free biosensing through the introduction of a sample solution.
authors.affiliation: Analytical Chemistry Group, Department of Applied Chemistry, Osaka Prefecture University, Sakai-shi, Osaka, Japan. endo@chem.osakafu-u.ac.jp
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Endo
authors.forename: Masaya
authors.initials: M
authors.lastname: Sato
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kajita
authors.forename: Norimichi
authors.initials: N
authors.lastname: Okuda
authors.forename: Satoru
authors.initials: S
authors.lastname: Tanaka
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hisamoto
mesh_terms: D000475:Alkenes / Q000737:chemistry; D000818:Animals; D055910:Antibodies, Immobilized / Q000276:immunology; D015374:Biosensing Techniques; D003460:Crystallization; D006801:Humans; D007328:Insulin / Q000032:analysis*; D055095:Optics and Photonics / Q000295:instrumentation* / Q000379:methods; D011108:Polymers / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013499:Surface Properties
chemical_list: D000475:Alkenes; D055910:Antibodies, Immobilized; D007328:Insulin; D011108:Polymers