title: A gold nanorod-based optical DNA biosensor for the diagnosis of pathogens.
abstract: A novel optical biosensor for detecting target DNA, utilizing gold nanorods (GNRs) as molecular probes is demonstrated. This sensor is based on simultaneous biorecognition-mediated hybridization of target DNA in a sandwich type manner with two different capture probe DNA sequences modified separately with identical sets of GNRs, which leads to aggregation of GNRs. The hybridization induced aggregation as revealed by TEM analysis, promotes the modulation of surface plasmon resonance of GNRs, which forms the basis of complementary target DNA detection from the Chlamydia trachomatis pathogen. Thermally induced reversible dissociation of hybridized DNA is demonstrated by melting analysis. The present sensing strategy is successfully demonstrated by detecting PCR amplified C. trachomatis pathogen gene isolated from human urine sample in a concentration range of 0.25-20 nM. Furthermore, this sensor displays excellent specificity by discriminating the target DNA versus other non-specific pathogenic genes.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors.forename: Harshala J
authors.initials: HJ
authors.lastname: Parab
authors.forename: Cheulhee
authors.initials: C
authors.lastname: Jung
authors.forename: Joo-Hyung
authors.initials: JH
authors.lastname: Lee
authors.forename: Hyun Gyu
authors.initials: HG
authors.lastname: Park
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002692:Chlamydia trachomatis / Q000235:genetics* / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry; D015336:Molecular Probe Techniques / Q000295:instrumentation*; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D055096:Optical Devices; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D004269:DNA, Bacterial; D006046:Gold