A wireless sensor platform design and a single walled carbon nanotube/ionic liquid-based chemidosimeter system can incorporated into a highly sensitive and selective chemical hazard badge that can dosimetrically detect an analyte down to a sub parts-per-million concentration.

Provided are biosensors, systems and related methods of using the biosensors and systems. The biosensor comprises a field-effect transistor (FET) having a crumpled geometry to effectively increase the detection sensitivity of a target molecule in an ionic solution. A FET having a crumpled semiconductor material channel can form a π-π interaction with single stranded DNA (ssDNA) for amplification detection applications. Increasing amount of ssDNA in an amplification reaction solution is incorporated into an amplified double stranded DNA, with increasing amplification, resulting in a lower amount of ssDNA primers. The FET is contacted with the amplified solution to electrically detect an amount of ssDNA primer in the amplified solution, thereby detecting amplification based on a decreased amount of ssDNA bound to the FET. Also provided are biosensors that can detect biomolecules more generally, such as protein, polypeptides, polynucleotides, or small molecules.

An organic electrochemical transistor, which includes a biologic detection layer and a catalytic layer, the latter being a composite material including noble metal nanoparticles and an organic conductive matrix. Also, a method for detection of a biological analyte wherein a biological fluid is contacted with such an organic electrochemical transistor.

Embodiments herein relate to systems and methods for utilizing hysteresis as a mechanism of analysis of a sample. A system for analyzing a fluid sample is included having a controller circuit and a chemical sensor element. The chemical sensor element can include one or more discrete binding detectors that can include one or more graphene varactors. The system can include measurement circuitry having an electrical voltage generator configured to generate an applied voltage at a plurality of voltage values to be applied to the one or more graphene varactors. The system can include a measurement circuit having a capacitance sensor configured to measure capacitance of the discrete binding detectors resulting from the applied voltage. The system for analyzing the fluid sample can be configured to measure hysteresis effects related to capacitance versus voltage values obtained from the one or more graphene varactors. Other embodiments are also included herein.

A device for interacting with a quantity of a sample, the device, comprising: a substrate comprising a first surface and a second surface, wherein the first surface is opposite to the second surface; an electrically-thin conductive layer disposed on the first surface of the substrate and configured to contact a first portion of the sample; a buried electrode disposed on the second surface of the substrate, the buried electrode being capacitively coupled with the electrically-thin conductive layer; and at least one electrode in contact with a second portion of the sample, wherein the second portion of the sample is remote from the first portion of the sample, and further wherein the at least one electrode and the electrically-thin conductive layer electrically interact via the sample; wherein the substrate is configured such that the substrate does not substantially conduct the flow of electric current through the electrically-thin conductive layer.

Provided are devices and methods to detect the presence of volatile organic compounds related to the presence of a disease state in a biological sample. The devices may include a detection moiety such as a polynucleoide in electronic communication with a semiconductor such as graphene or a carbon nanotube.

A self-healing field-effect transistor (FET) device is disclosed in this application, the self-healing FET has a self-healing substrate, a self-healing dielectric layer, a gate electrode, at least one source electrode, at least one drain electrode, and at least one channel. The self-healing substrate and the self-healing dielectric layer have a disulfide-containing poly(urea-urethane) (PUU) polymer. The self-healing dielectric layer has a thickness of less than about 10 .Math.m. The electrodes have electrically conductive elongated nanostructures. The at least one channel has semi-conducting elongated nanostructures.

Described herein is a portable virometer for detecting viral targets. An exemplary virometer has a molecular electronics sensor with a first electrode, a second electrode spaced-apart from the first electrode by a nanogap, a bridge molecule having a first end and a second end, the first end coupled to the first electrode and the second end coupled to the second electrode, a hybridization probe having an oligonucleotide sequence from or related to a viral target is conjugated to the bridge molecule, a sample applicator for acquiring a sample and transferring it to the chip, and data processing software and hardware for providing a report of detection of viral targets. Methods of using the virometer for testing in the home, in schools, in workplaces, in hotels, in restaurants, or in public places are also described.

A chemical sensor apparatus includes a buffer solution including not less than 0.5 mM and not more than 6 mM of chlorine ions; a sensor element including a surface immersed in the buffer solution; and a silver/silver chloride electrode immersed in the buffer solution. The silver/silver chloride electrode applies a potential to the buffer solution, and includes silver chloride at a surface of the silver/silver chloride electrode.

Embodiments herein include a kinetic response system for measuring analyte presence on a chemical sensor element. The chemical sensor element includes one or more discrete binding detectors, each discrete binding detector including a graphene varactor. The kinetic response system includes a measurement circuit having an excitation voltage generator for generating a series of excitation cycles over a time period. Each excitation cycle includes delivering a DC bias voltage to the discrete binding detectors at multiple discrete DC bias voltages across a range of DC bias voltages. The kinetic response system includes a capacitance sensor to measure capacitance of the discrete binding detectors resulting from the excitation cycles. The kinetic response system includes a controller circuit to determine the kinetics of change in at least one of a measured capacitance value and a calculated value based on the measured capacitance over the time period. Other embodiments are also included herein.