One-dimensional nanostructures based bio-detection.

This paper presents a review on recent developments of one-dimensional (1-D) nanostructures based label-free chemiresistive/chemFET biosensors and the various sensing mechanisms used for biomolecular detection. The sensor performance including sensitivity, selectivity, and reliability is compared in terms of material synthesis of the sensor's element, relating surface functionalization schemes to their properties with respect to selected bioreceptors, its method of fabrication, and its intended operation. As a final point, we outline the prospects of chemiresistive/chemFET biosensors and recommend specific advancements in this field.

Polyaniline/poly(ε-caprolactone) composite electrospun nanofiber-based gas sensors: optimization of sensing properties by dopants and doping concentration.

Electrospinning was utilized to synthesize a polyaniline (PANI)/poly(ε-caprolactone) (PCL) composite in the form of nanofibers to examine its gas sensing performance. Electrical conductivity of the composite nanofibers was tailored by secondary doping with protonic acids including hydrochloride (HCl) or camphorsulfonic acid (HCSA). FT-IR and diffuse reflectance UV-vis spectroscopy were utilized to examine doping-dependent changes in the chemical structure and the protonation state of the nanofibers, respectively.

Palladium/single-walled carbon nanotube back-to-back Schottky contact-based hydrogen sensors and their sensing mechanism.

A Schottky contact-based hydrogen (H2) gas sensor operable at room temperature was constructed by assembling single-walled carbon nanotubes (SWNTs) on a Si/SiO2 substrate bridged by Pd microelectrodes in a chemiresistive/chemical field effect transistor (chemFET) configuration. The Schottky barrier (SB) is formed by exposing the Pd-SWNT interfacial contacts to H2 gas, the analyte it was designed to detect. Because a Schottky barrier height (SBH) acts as an exponential bottleneck to current flow, the electrical response of the sensor can be particularly sensitive to small changes in SBH, yielding an enhanced response to H2 gas.

Tuning the gas sensing performance of single PEDOT nanowire devices.

This paper reports the synthesis and dopant dependent electrical and sensing properties of single poly(ethylenedioxythiophene) (PEDOT) nanowire sensors. Dopant type (i.e.

Synthesis of Sn doped CuO nanotubes from core-shell Cu/SnO(2) nanowires by the Kirkendall effect.

Sn doped CuO nanotubes were synthesized by thermal oxidization of Cu/SnO(2) core-shell nanowires in air through the Kirkendall effect. The Cu/SnO(2) core-shell nanowires were sequentially electrodeposited by forming a SnO(2) shell followed by electrodeposition of the Cu core. After thermal treatment in air, the core-shell Cu/SnO(2) (13 +/- 2 nm thick shell on 128 +/- 15 nm in diameter core) nanowires were oxidized to form Sn doped CuO nanotubes with an average wall thickness and outer diameter of 54 nm and 176 nm, respectively.

Sensitive detection of H2S using gold nanoparticle decorated single-walled carbon nanotubes.

Herein, we demonstrate that highly sensitive conductometric gas nanosensors for H(2)S can be synthesized by electrodepositing gold nanoparticles on single-walled carbon nanotube (SWNT) networks. Adjusting the electrodeposition conditions allowed for tuning of the size and number of gold nanoparticles deposited. The best H(2)S sensing performance was obtained with discrete gold nanodeposits rather than continuous nanowires.