title: Oligonucleotide-arrayed TFT photosensor applicable for DNA chip technology.
abstract: A thin film transistor (TFT) photosensor fabricated by semiconductor integrated circuit (IC) technology was applied to DNA chip technology. The surface of the TFT photosensor was coated with TiO2 using a vapor deposition technique for the fabrication of optical filters. The immobilization of thiolated oligonucleotide probes onto a TiO2-coated TFT photosensor using gamma-aminopropyltriethoxysilane (APTES) and N-(gamma-maleimidobutyloxy) sulfosuccinimide ester (GMBS) was optimized. The coverage value of immobilized oligonucleotides reached a plateau at 33.7 pmol/cm2, which was similar to a previous analysis using radioisotope-labeled oligonucleotides. The lowest detection limits were 0.05 pmol/cm2 for quantum dot and 2.1 pmol/cm2 for Alexa Fluor 350. Furthermore, single nucleotide polymorphism (SNP) detection was examined using the oligonucleotide-arrayed TFT photosensor. A SNP present in the aldehyde dehydrogenase 2 (ALDH2) gene was used as a target. The SNPs in ALDH2*1 and ALDH2*2 target DNA were detected successfully using the TFT photosensor. DNA hybridization in the presence of both ALDH2*1 and ALDH2*2 target DNA was observed using both ALDH2*1 and ALDH2*2 detection oligonucleotides-arrayed TFT photosensor. Use of the TFT photosensor will allow the development of a disposable photodetecting device for DNA chip systems.
authors.affiliation: Department of Biotechnology, Tokyo University of Agriculture & Technology, Koganei, Tokyo 184-8588, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tanaka
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sawaguchi
authors.forename: Akihito
authors.initials: A
authors.lastname: Iwadate
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sasaki
authors.forename: Naofumi
authors.initials: N
authors.lastname: Tateishi
authors.forename: Haruko
authors.initials: H
authors.lastname: Takeyama
authors.forename: Tadashi
authors.initials: T
authors.lastname: Matsunaga
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000032:analysis* / Q000737:chemistry / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017404:In Situ Hybridization, Fluorescence / Q000295:instrumentation* / Q000379:methods; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014173:Transistors, Electronic
chemical_list: D004247:DNA