The covalent attachment of disulfide-modified oligonucleotides to a mercaptosilane-modified glass surface is described. This method provides an efficient and specific covalent attachment chemistry for immobilization of DNA probes onto a solid support. Glass slides were derivatized with 3-mercaptopropyl silane for attachment of 5-prime disulfide-modified oligonucleotides via disulfide bonds. An ...

We describe the use of self-assembled films of thiolated (dT)25 single-stranded DNA (ssDNA) on gold as a model system for quantitative characterization of DNA films by X-ray photoelectron spectroscopy (XPS). We evaluate the applicability of a uniform and homogeneous overlayer-substrate model for data analysis, examine model parameters used to describe DNA films (e.g., density and electron atten...

Healing canine flexor tendons treated with either total immobilization, delayed protected mobilization, or early protected mobilization was studied by biomechanical, microangiographic, biochemical, and histologic techniques at intervals through 12 weeks. The healing characteristics of the early mobilization tendons showed higher tensile strengths and improved gliding function than the delayed m...

Magnetic silica aerogel in hydrophobic and hydrophilic forms were used as support to immobilize Candida rugosa lipase by adsorption method. Response surface methodology (RSM) was employed to study the effects of the three most important immobilization parameters, namely enzyme/support ratio (0.3-0.5, w/w), immobilization time (60-120 min) and alcohol percentage (20-40, %v/v) on the specific act...

A chemically modified graphene paste electrode was prepared by incorporating appropriate amounts of graphene in a paste mixture, followed by electrodepositing Prussian blue (PB) and coating chitosan on the electrode surface. The electrode was able to bind ssDNA, and gave a better voltammetric response for complement DNA than did ordinary carbon paste electrodes. The response of the electrode wa...

We report the selective and real-time detection of label-free DNA using an electronic readout. Microfabricated silicon field-effect sensors were used to directly monitor the increase in surface charge when DNA hybridizes on the sensor surface. The electrostatic immobilization of probe DNA on a positively charged poly-l-lysine layer allows hybridization at low ionic strength where field-effect s...

Scanning electrochemical microscopic (SECM) imaging of oligonucleotides and polynucleotides (poly[G] and calf thymus DNA) immobilized onto aldehyde-modified glass substrates was achieved through oxidation of guanine residues on the DNA molecules by SECM tip-generated Ru(bpy)3 3 . Several parameters affecting the tip current associated with the guanine oxidation reaction (e.g. tip/substrate sepa...

We present here results that demonstrate the formation of a complex of DNA with zwitterionic dipalmitoylphosphatidylcholine (DPPC) monolayer at the air-water interface in the presence of Ca2+ ions; in particular, we show that the presence of Ca2+ cations is essential for the formation of the complex of DPPC with DNA. We characterize the resulting structure by X-ray reflectivity and by null-elli...

objective(s): enzyme immobilization via nanoparticles is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. in this study lactoperoxidase was immobilized onto silica-coated magnetite nanoparticles to improve enzyme properties in the presence of cadmium chloride as an inhibitor. materials and methods:  the process consists of the ...

We have coupled a novel isothermal amplification method for short oligonucleotides (EXPAR) with solution and surface-based detection involving DNA-functionalized gold nanospheres. The assay allows for different target sequences to be detected using the same set of DNA:Au nanospheres through appropriately designed reporter sequences. The solution based assay relies on simple visual detection thr...