MIT News December 20, 2024 Monitoring electrical potentials in liquid is critical in biosensing but limitations in spatial resolution and recording density remain. A team of researchers in the US (MIT, industry) introduced organic electro-scattering antennas (OCEANs) for wireless, light-based probing of electrical signals with micrometer spatial resolution, potentially from thousands of sites. The technology relied on poly(3,4-ethylenedioxythiophene):polystyrene sulfonate light scattering properties to its doping level. Signal-to-noise ratios up to 48 were achieved in response to 100-mV stimuli. OCEANs demonstrated millisecond time constants and long-term stability, enabled continuous recordings over 10 hours. According to the researchers their work potentially accelerates […]
Tag Archives: Biosensing
Tiny chips promise swift disease diagnosis from a single breath
Phys/org December 16, 2024 Field-effect transistor (FET)-based electronic biosensing platforms are particularly attractive due to their sensitivity, fast turn-around time, potential for parallel detection of multiple pathogens, and compatibility with semiconductor manufacturing. However, scalability multiplexed biofunctionalization, nanoscale precision for immobilizing different types of pathogen-specific bioreceptors, are unmet. An international team of researchers (USA – New York University, SUNY Downstate Health Sciences University, industry, Italy) proposed a paradigm shift in FET biofunctionalization using thermal scanning probe lithography (tSPL) with a thermochemically sensitive polymer which could be spin-coated on fully fabricated FET chips, making this approach applicable to any FET sensor material […]
New ion speed record holds potential for faster battery charging and biosensing
Phys.org November 19, 2024 Organic mixed ionic-electronic conductors (OMIECs) have better properties than inorganic counterparts for biosensing, soft-robotics, neuromorphic computing, and smart medicine. However, slow ion transport relative to charge transport in these materials is a limiting factor. Researchers at Washington State University demonstrated that hydrophilic molecules local to an interfacial OMIEC nanochannel could accelerate ion transport with ion mobilities surpassing electrophoretic transport by more than an order of magnitude. Ion access to the interfacial channel could be gated through local surface energy. They applied the mechanism in a novel sensing device, which electronically detected and characterized chemical reaction dynamics […]
Successful optical biosensing using dual optical combs: High sensitivity and rapid detection of biomolecules
Phys.org September 26, 2023 Rapid, sensitive detection of biomolecules is important for biosensing of infectious pathogens as well as biomarkers and pollutants. Researchers in Japan have achieved rapid and sensitive detection of SARS-CoV-2 nucleocapsid protein antigen by enhancing the performance of optical biosensing based on optical frequency combs (OFC). The virus-concentration-dependent optical spectrum shift produced by antigen–antibody interactions was transformed into a photonic RF shift by a frequency conversion between the optical and RF regions in the OFC, facilitating rapid and sensitive detection with well-established electrical frequency measurements. The active-dummy temperature-drift compensation with a dual-comb configuration enabled the very small […]
A new platform for customizable quantum devices
Phys.org February 24, 2022 A team of researchers in the US (MIT, Columbia University, University of Chicago, Northwestern University) focused on a group of molecules with a central chromium atom surrounded by four hydrocarbon molecules to demonstrate how a particular molecular family of qubits can be finely tuned over a broad spectrum. They used synthetic chemistry to modify the physics of the qubits. Using the ligand field strength, they demonstrated remarkable fine tuning and showed that the ligand field strengths are adjustable over a relatively broad spectrum, and that it also controls the molecule’s electronic properties. The light emitted by […]
Team demonstrates molecular electronics sensors on a semiconductor chip
Phys.com January 25, 2022 A team of researchers in the US (industry, UC San Diego, Rice University, Harvard University) has developed a molecular electronics platform which consists of a programmable semiconductor chip with a scalable sensor array architecture. Each array element consists of an electrical current meter that monitors the current flowing through a precision-engineered molecular wire, assembled to span nanoelectrodes that couple it directly into the circuit. The sensor is programmed by attaching the desired probe molecule to the molecular wire, via a central, engineered conjugation site. The observed current provides a direct, real-time electronic readout of molecular interactions […]
Novel biosensors set to revolutionize brain-controlled robotics
Science Daily December 22, 2021 Researchers in Australia have detected the EEG signals with high sensitivity using epitaxial graphene (EG) grown on silicon carbide on silicon. The dry and non-invasive approach exhibited a markedly improved skin contact impedance when benchmarked to commercial dry electrodes, as well as superior robustness, allowing prolonged and repeated use also in a highly saline environment. They observed a new phenomenon of surface conditioning of the EG electrodes. The prolonged contact of the EG with the skin electrolytes functionalize the grain boundaries of the graphene, leading to the formation of a thin surface film of water […]
Scientists create tiny lasers from nanoparticles and plastic beads
Nanowerk December 30, 2019 An international team of researchers (Lawrence Berkeley National Laboratory, UC Berkeley, Columbia University, Italy, Kazakhstan) found that when an infrared laser excites thulium-doped nanoparticles coated on the surface of the beads, the light emitted by the nanoparticles bounces around the inner surface of the bead. When the intensity of light traveling around these beads reaches a certain threshold, the light can stimulate the emission of more light with the exact same color producing intense light at a very narrow range of wavelengths in the beads. When the team exposed the beads to an infrared laser with […]
Nanoscale manipulation of light leads to exciting new advancement
Eurekalert October 11, 2019 Researchers at the University of New Mexico studied arrays composed of silver nanoparticles placed in a repeating pattern. When the arrays are illuminated with light, each of the particles produces a strong response, which, in turn, results in enormous collective behaviors if all the particles can interact with one another. This happens at certain wavelengths of incident light, which are determined by the interparticle spacing of the array, and can result in electric fields that are thousands, or even tens of thousands, of times that of the light shined on the array. The strength of this […]