A field effect transistor and a sensor using the field effect transistor is provided. The field effect transistor can be manufactured so as to have uniform properties by simple steps at low costs, and can stably detect, when used as a sensor, a very small amount of analyte with a high sensitivity while the properties are hardly deteriorated. A channel of the field effect transistor is constituted by a single-walled carbon nanotube thin film that is grown, by a chemical vapor deposition method, using particles of a nonmetallic material as growth nuclei, the nonmetallic material containing 500 mass ppm or less metallic impurities that contain a metal and its compounds.

A single chirality single walled carbon nanotubes (SWNT), and combinations thereof, can be used to detect trace levels of chemical compounds in vivo with high selectivity.

The method for producing noble metal nanocomposites involves reducing noble metal ions (Ag, Au and Pt) on graphene oxide (GO) or carbon nanotubes (CNT) by using Artocarpus integer leaves extract as a reducing agent. As synthesized MNPs/GO and MNPs/CNT composites have been characterized using X-ray diffraction (XRD), transmission electron microscope (TEM) imaging, and energy dispersive X-ray spectroscopy (EDX). The TEM images of prepared materials showed that the nanocomposites were 1-30 nm in size with spherical nanoparticles embedded on the surface of GO and CNT. This synthetic route is easy and rapid for preparing a variety of nanocomposites. The method avoids use of toxic chemicals, and the prepared nanocomposites can be used for biosensor, fuel cell, and biomedical applications.

This disclosure relates to a glucose-sensing electrode including a nanoporous metal layer and a maltose-blocking layer formed over the nanoporous metal layer. The nanoporous metal layer is capable of oxidizing both glucose and maltose without an enzyme specific to glucose or maltose in the glucose-sensing electrode. The maltose-blocking layer has porosity that permits glucose to pass therethrough and inhibits maltose from passing therethrough toward the nanoporous metal layer.

Systems comprising a nanocrystal and a luminescent chromophore are disclosed herein. The luminescent chromophore can emit energy having a first wavelength. The luminescent chromophore is configured to transfer the emitted energy having a first wavelength to the nanocrystal. The luminescent chromophore can be linked to the nanocrystal via a covalent bond. Absorption of the energy having first wavelength by the nanocrystal can activate the nanocrystal and result in an increase in quantum yield. In some embodiments, the nanocrystal can include silicon, germanium, carbon, or combinations thereof. In some examples, the luminescent chromophore can be pyrene. The luminescent chromophore and the silicon containing nanocrystal can be in a ratio of about 1:1 to 100:1 in the nanocrystal system. Methods of making and using the system are also disclosed.

This disclosure relates to a glucose-sensing electrode including a nanoporous metal layer and an electrolyte ion-blocking layer formed over the nanoporous metal layer. The nanoporous metal layer is capable of oxidizing both glucose and maltose without an enzyme specific to glucose in the glucose-sensing electrode. The electrolyte ion-blocking layer is configured to inhibit Na.sup.+, K.sup.+, Ca.sup.2+, Cl.sup.−, PO.sub.4.sup.3− and CO.sub.3.sup.2− from diffusing toward the nanoporous metal layer such that there is a substantial discontinuity of a combined concentration of Na.sup.+, K.sup.+, Ca.sup.2+, Cl.sup.−, PO.sub.4.sup.3− and CO.sub.3.sup.2− between over and below the electrolyte ion-blocking layer.

Imaging based detection of changes in extracellular neurotransmitter concentration in living tissue is achieved using novel nanotube-based sensors. The sensors are functionalized, neurocompatible single-walled carbon nanotubes (SWNT) comprising an adsorbed neurotransmitter analyte selective polynucleotide.

This application features a method of forming a nanoporous layer. The method includes steps of dispensing on a substrate a colloid composition comprising a liquid and a number of nanoparticle clusters, and subjecting the dispensed colloid composition to drying to form the nanoporous layer over the substrate. The nanoporous layer includes nanoparticles deposited to form a three dimensional network of irregularly shaped bodies. The nanoporous layer also includes a three dimensional network of irregularly shaped spaces that are not occupied by the three dimensional network of irregularly shaped bodies.

This disclosure relates to a glucose-sensing electrode including a nanoporous metal layer and an electrolyte ion-blocking layer formed over the nanoporous metal layer. The nanoporous metal layer is capable of oxidizing both glucose and maltose without an enzyme specific to glucose in the glucose-sensing electrode. The electrolyte ion-blocking layer is configured to inhibit Na.sup.+, K.sup.+, Ca.sup.2+, Cl.sup.−, PO.sub.4.sup.3− and CO.sub.3.sup.2− from diffusing toward the nanoporous metal layer such that there is a substantial discontinuity of a combined concentration of Na.sup.+, K.sup.+, Ca.sup.2+, Cl.sup.−, PO.sub.4.sup.3− and CO.sub.3.sup.2− between over and below the electrolyte ion-blocking layer.

This disclosure relates to an apparatus for glucose-sensing that address interference of ascorbic acid and acetaminophen. The apparatus includes a first electrode capable of oxidizing glucose and at least one of ascorbic acid and acetaminophen. The apparatus further includes a second electrode capable of oxidizing at least one of ascorbic acid and acetaminophen but not capable of oxidizing glucose. The first electrode includes a deposit of irregularly shaped bodies that are formed of numerous nanoparticles having a generally oval or spherical shape with a length ranging between about 2 nm and about 5 nm. The deposit is substantially free of a surfactant. If any surfactant is contained in the deposit, the surfactant is in an amount smaller than 0.5 parts by weight with reference to 100 parts by weight of the deposit. The first electrode does not include a glucose-specific enzyme.