Silica-nanoparticle-based interface for the enhanced immobilization and sequence-specific detection of DNA.
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.
Zhang
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D
Key Laboratory of Life Analytical Chemistry, Department of Chemistry, Nanjing University, 210093 Nanjing, China.
Chen
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Y
Chen
H-Y
HY
Xia
X H
XH
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
D004277:DNA, Single-Stranded; D006046:Gold; D012822:Silicon Dioxide; D004247:DNA; C427203:calf thymus DNA