title: Combinable poly(dimethyl siloxane) capillary sensor array for single-step and multiple enzyme inhibitor assays.
abstract: We describe a new method for fabricating a capillary-type sensor, called a combinable poly(dimethyl siloxane) (PDMS) capillary (CPC) sensor. The method for preparing the CPC simplifies enzyme inhibitor assays into a simple, single step assay. The sample inhibitor solution is introduced by capillary action. This triggers the spontaneous dissolution of physically adsorbed fluorescent substrates, and the substrate mixes with the inhibitor. This is followed by competitive reaction with insoluble enzyme to give a fluorescence response. CPC is composed of a convex-shaped PDMS stick containing reagents immobilized in an insoluble coating, and a concave-shaped PDMS stick containing reagents immobilized in a soluble coating. Since the concave-shaped PDMS has a deeper channel than the convex structure, combining these PDMS sticks is like closing the zipper of a "freezer bag". This allows easy fabrication of "thin and long" capillary structures containing different reagents inside the same capillary, without the need for precise alignment. This method allows the immobilization of two reactive reagents, such as enzyme and substrate required for a single step assay, which are typically very difficult to immobilize using commercially available conventional capillaries. Furthermore, by simply arraying various CPCs, the CPC sensor allows multiple assays. Here, we carried out a single-step enzyme inhibitor assay using the CPC. In addition, two independent CPCs were arrayed to demonstrate multiple assaying of a protease inhibitor.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai City, Osaka 599-8531, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Uchiyama
authors.forename: Fumito
authors.initials: F
authors.lastname: Okubo
authors.forename: Kozo
authors.initials: K
authors.lastname: Akai
authors.forename: Yuji
authors.initials: Y
authors.lastname: Fujii
authors.forename: Terence G
authors.initials: TG
authors.lastname: Henares
authors.forename: Kunio
authors.initials: K
authors.lastname: Kawamura
authors.forename: Toshio
authors.initials: T
authors.lastname: Yao
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Endo
authors.forename: Hideaki
authors.initials: H
authors.lastname: Hisamoto
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D057075:Enzyme Assays / Q000295:instrumentation* / Q000379:methods; D004791:Enzyme Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D004867:Equipment Design; D005456:Fluorescent Dyes / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation; D008954:Models, Biological; D015203:Reproducibility of Results
chemical_list: D004129:Dimethylpolysiloxanes; D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D005456:Fluorescent Dyes; C013830:baysilon