Multisegment Nanowire Sensors for the Detection of DNA Molecules

Abstract

We describe a novel application for detecting specific single strand DNA sequences using multisegment nanowires via a straightforward surface functionalization method. Nanowires comprising CdTe−Au−CdTe segments are fabricated using electrochemical deposition, and electrical characterization indicates a p-type behavior for the multisegment nanostructures, in a back-to-back Schottky diode configuration. Such nanostructures modified with thiol-terminated probe DNA fragments could function as high fidelity sensors for biomolecules at very low concentration. The gold segment is utilized for functionalization and binding of single strand DNA (ssDNA) fragments while the CdTe segments at both ends serve to modulate the equilibrium Fermi level of the heterojunction device upon hybridization of the complementary DNA fragments (cDNA) to the ssDNA over the Au segment. Employing such multisegment nanowires could lead to the fabrication more sophisticated and high multispecificity biosensors via selective functionalization of individual segments for biowarfare sensing and medical diagnostics applications.Nanowire-based field-effect transistors (FET) have been widely used for detection of a variety of biological and chemical species, detection of PH value, detection of metal ions, viruses, proteins, etc. [1][2][3][4] In most of these applications, the mechanism of sensing is based on the functionalization of a homogeneous semiconducting nanowire, such as silicon 4 and In 2 O 3 nanowires. 5 There is a growing interest in fabricating heterojunction nanowires, which show great potential for applications in nanoelectronics, 6 energy conversion, 7 self-assembly, 8 and controlled positioning of nanowire arrays. 9 Generally, there are two basic morphologies in nanowire heterostructures: radial heterostructures, such as core-shell nanowires, and axial heterostructures, comprising multisegment nanowires. Core-shell nanowires have been used to fabricate coaxially gated nanowire transistors. 10,11 Multisegment nanowires comprise several different material compositions or phases along its length, and their synthesis have been demonstrated in a variety of configurations including the growth of nanowire superlattices via alternating laser ablation of different solid targets. The superlattices inside the nanowires make them engineered materials having a high thermoelectric coefficient, 12 possible uses in p-n junction diodes, 13 and with notable optical properties via photoluminescence characterization. 14 Electrochemical template synthesis is a versatile technique for producing multisegment nanowires, in which individual segments could be metallic, oxide, binary, or ternary alloys and semiconducting and conducting polymers. And specific functionality including optical, magnetic, or electrical properties could be introduced. Multisegment metallic nanowires synthesized by electrochemistry have been assembled endto-end by using different linkages, such as biomolecules [15][16][17][18] and polymers. 19 Nanowires capped with magnetic met...

Synthesis of Vertically Aligned CuO Nanorods by Thermal Oxidation

“…그 중 나노선 구조는 여러가지 물질을 나노단위 두께의 선형태로 성장시킨 구조로써, 표면적이 크다는 구조적인 특성상 센서, [3][4][5][6][7][8][9] 태양전지, 10-12) 의료 [13][14][15][16] …”

Towards Nanowire (Bio) Sensors

“…[1] The emerging trend for point-of-care instrumentation is driving the development of miniaturized systems capable of reliable and rapid quantification of a wide range of biomolecules. [2][3][4][5] To address this opportunity, nanosensors based on one-dimensional nanostructures such as silicon nanowires and carbon nanotubes FET devices are being explored since these nanostructures offer the potential to achieve highly sensitive integrated sensors with direct electrical readout. [6][7][8] In these sensor systems, the perturbation in the local electrostatic environment of a nanowire-based FET by a charged analyte alters the conductance, which is employed as the sensor signal.…”

“…[10] Nanowires represent a new and emerging powerful class of sensors and to date have been utilized for direct, sensitive and rapid detection of biological and chemical species. [2,3,[11][12][13][14] Noble metal nanowires such as gold, platinum and silver, are of particular importance due to their excellent 1 To whom any correspondence should be addressed. …”

Thionin attached to a gold electrode modified with self-assembly of Mo6S9−I nanowires for amplified electrochemical detection of natural DNA

“…Various electrochemical sensing platforms based on namomaterials such as carbon nanotubes (Zhang et al, 2009a,b;Zhu et al, 2009), nanoparticles (Das and Yang, 2009;Du et al, 2009;Li et al, 2009) and nanowires (Chen et al, 2009;Wang and Ozkan, 2008) have been reported. These studies indicate that nanomaterials are making a big impact on development of electrochemical biosensors and nanotechnology is bringing new possibilities for improving both the sensitivity and selectivity of biosensing devices.…”