We investigate the effect of functional groups of pyrene molecules on the electrical sensing performance of single-walled carbon nanotubes (SWNTs) based DNA biosensor, in which pyrenes with three different functional groups of carboxylic acid (Py-COOH), aldehyde (Py-CHO) and amine (Py-NH2) are used as linker molecules to immobilize DNA on the SWNT films. UV/Visible absorption spectra results sh...

This article reports on the syntheses, characterization and applications of semi-synthetic conjugates composed of nucleic acids, proteins and inorganic nanoparticles. For example, self-assembled oligomeric networks consisting of streptavidin and double-stranded DNA are applicable as reagents in immunoassays, model systems for ion-switchable nanoparticle networks as well as nanometer-scaled 'sof...

A nonlabeling electrochemical detection method for analyzing the polymerase-chain-reaction-amplified sequence-specific p16 ( INK4A ) gene, in which the basis for the covalent immobilization of deoxyribonucleic acid (DNA) probe is described, has been developed. The self-assembly process was based on the covalent coupling of glutaraldehyde (GA) as an arm molecule onto an amino-functional surface....

An assay for very sensitive antigen detection is described which takes advantage of the self- assembly capabilities of semi-synthetic conjugates of DNA and proteins. The general scheme of this assay is similar to a two-sided (sandwich) enzyme-linked immunoassay (ELISA); however, covalent single-stranded DNA-streptavidin (STV) conjugates, capable of hybridizing to complementary surface-bound DNA...

Development of a simple and efficient methodology to control the placement, spacing, and alignment of single-walled carbon nanotubes (SWCNTs) is essential for nanotechnology device application. Building on the growing understanding that the strong π-π interaction between the bases of single-stranded DNA (ssDNA) and CNTs is sufficient not only to drive CNT solubility in water but also to stabili...

Efficient near-infrared detection of specific DNA with single nucleotide polymorphism selectivity is important for diagnostics and biomedical research. Herein, we report the use of gallium arsenide (GaAs) as a sensing platform for probing DNA immobilization and targeting DNA hybridization, resulting in ∼8-fold enhanced GaAs photoluminescence (PL) at ∼875 nm. The new signal amplification strateg...

Dielectrophoretic trapping of six different DNA fragments, sizes varying from the 27 to 8416 bp, has been studied using confocal microscopy. The effect of the DNA length and the size of the constriction between nanoscale fingertip electrodes on the trapping efficiency have been investigated. Using finite element method simulations in conjunction with the analysis of the experimental data, the p...

We are working towards the construction of hybrid bioelectronic systems in which DNA nanomachines are integrated with semiconductor circuitry, where DNA performs the function of highly parallel, low-power processing of biomolecular signals, and silicon is used for high-speed data processing and control. This technology has applications in computation and smart biosensing, and surface immobiliza...

BACKGROUND Micrometer resolution placement and immobilization of probe molecules is an important step in the preparation of biochips and a wide range of lab-on-chip systems. Most known methods for such a deposition of several different substances are costly and only suitable for a limited number of probes. In this article we present a flexible procedure for simultaneous spatially controlled imm...