title: Silica-nanoparticle-based interface for the enhanced immobilization and sequence-specific detection of DNA.
abstract: A biocompatible and uniform interface based on silica nanoparticles derivatized with amino groups has been constructed for the effective immobilization and sensitive sequence-specific detection of calf thymus DNA. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) results showed that a monolayer of silica nanoparticles can be formed on a gold electrode under our experimental conditions using cysteine self-assembly monolayer as binder medium. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy (XPS) verified the successful immobilization of DNA on silica-nanoparticle-modified gold electrodes. Quantitative results demonstrated that enhanced immobilization of single-strand DNA (ss-DNA) up to 1.6 x 10(-8) mol cm(-2) could be achieved owing to the larger surface area and the special properties of silica nanoparticles. In addition, hybridization experiments demonstrated that the immobilized ss-DNA on silica nanoparticles could specifically interact with complementary DNA in solutions.
authors.affiliation: Key Laboratory of Life Analytical Chemistry, Department of Chemistry, Nanjing University, 210093 Nanjing, China.
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: H-Y
authors.initials: HY
authors.lastname: Chen
authors.forename: X H
authors.initials: XH
authors.lastname: Xia
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D007103:Immobilization; D049329:Nanostructures / Q000737:chemistry*; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA / Q000379:methods*; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D004277:DNA, Single-Stranded; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA; C427203:calf thymus DNA