title: Multianalyte immunoassay with self-assembled addressable microparticle array on a chip.
abstract: This paper describes the random fluidic self-assembly of metallic particles into addressable two-dimensional microarrays and the use of these arrays as a platform for constructing a biochip useful for bioassays. The basic units in the assembly were the microfabricated particles carrying a straightforward visible code and the corresponding array template patterned on a glass substrate. The particles consisted of a hydrophobic and magnetic Ni-polytetrafluoroethylene (PTFE) composite layer on one face, and on the other face a gold layer that was modified for biomolecular attachment. An array template was photoresist-patterned with spatially discrete microwells in which an electrodeposited Ni-PTFE hydrophobic composite layer and a hydrophobic photo-adhesive coating were deposited. The particles, after biomaterial attachment and binding processes in bulk, were self-assembled randomly onto the lubricated bonding sites on the chip substrate, driven by a combination of magnetic, hydrophobic, and capillary interactions. The encoding symbol carried by the particles was used as the signature for the identification of each target/assay attached to the particle surface. We demonstrate here the utility of microfabricated-encoded particle arrays for conducting multianalyte immunoassays in a parallel fashion with the use of imaging detection.
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Tatsunokuchi, Ishikawa 923-1292, Japan.
authors.forename: Zheng-liang
authors.initials: ZL
authors.lastname: Zhi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Murakami
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Morita
authors.forename: Quamrul
authors.initials: Q
authors.lastname: Hasan
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D001681:Biological Assay / Q000295:instrumentation / Q000379:methods; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D002138:Calibration; D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation* / Q000379:methods*; D044085:Microfluidics