title: Label-free detection of peptide nucleic acid-DNA hybridization using localized surface plasmon resonance based optical biosensor.
abstract: The development of label-free optical biosensors for DNA and other biomolecules has the potential to impact life sciences as well as screening in medical and environmental applications. In this report, we developed a localized surface plasmon resonance (LSPR) based label-free optical biosensor based on a gold-capped nanoparticle layer substrate immobilized with peptide nucleic acids (PNAs). PNA probe was designed to recognize the target DNA related to tumor necrosis factor. The nanoparticle layer was formed on a gold-deposited glass substrate by the surface modified silica nanoparticles using silane-coupling reagent. The optical properties of gold-capped nanoparticle layer substrate were characterized through monitoring the changes in the absorbance strength, as the thickness of the biomolecular layer increased with hybridization. The detection of PNA-DNA hybridization with target oligonucleotides and PCR-amplified real samples were performed with a limit of detection value of 0.677 pM target DNA. Selective discrimination against a single-base mismatch was also achieved. Our LSPR-based biosensor with the gold-capped nanoparticle layer substrate is applicable to the design of biosensors for monitoring of the interaction of other biomolecules, such as proteins, whole cells, or receptors with a massively parallel detection capability in a highly miniaturized package.
authors.affiliation: Department of Biological Science and Biotechnology, School of Material Science, Japan Advanced Institute of Science and Technology, Nomi City, Ishikawa 923-1292, Japan.
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Endo
authors.forename: Kagan
authors.initials: K
authors.lastname: Kerman
authors.forename: Naoki
authors.initials: N
authors.lastname: Nagatani
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Takamura
authors.forename: Eiichi
authors.initials: E
authors.lastname: Tamiya
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000737:chemistry*; D015342:DNA Probes / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D020135:Peptide Nucleic Acids / Q000737:chemistry*; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D015342:DNA Probes; D020135:Peptide Nucleic Acids; D004247:DNA