Graphene underpins a new platform to selectively ID deadly strains of bacteria

Technology.org  March 24, 2020 Point-of-care diagnostics that can reduce and/or prevent unneeded antibiotic prescriptions require highly specific probes with sensitive and accurate transducers that can be miniaturized and multiplexed, and that are easy to operate and cheap. Researchers at Boston College present several advances in the use of graphene field effect transistors (G-FET) including the first use of peptide probes to electrically detect antibiotic resistant bacteria in a highly specific manner. They have reduced the needed concentration for detection by employing dielectrophoresis which allows monitoring changes in the Dirac point due to individual bacterial cells. Rapid binding of bacterial cells […]

Atomic fingerprint identifies emission sources of uranium

Science Daily  March 9, 2020 Isotopic ratios of radioactive releases into the environment are useful signatures for contamination source assessment. A ratio of uranium trace isotopes may serve as a superior oceanographic tracer. An international team of researchers (Austria, Australia, Denmark, Japan, Germany) analysed ratio on the atomic 233U/236U ratio analyzed in representative environmental samples. The ratios detected in compartments of the environment affected by releases of nuclear power production or by weapons fallout differ by one order of magnitude. Significant amounts of 233U were only released in nuclear weapons fallout. This makes the 233U/236U ratio a promising new fingerprint […]

A new AI chip can perform image recognition tasks in nanoseconds

MIT Technology Review  March 4, 2020 Visual information is captured by a frame-based camera, converted into a digital format and processed afterwards using a machine-learning algorithm such as an artificial neural network (ANN). The large amount of data passed through the entire signal chain, however, results in low frame rates and high-power consumption. Researchers in Austria built a sensor based on a reconfigurable two-dimensional semiconductor photodiode array, and the synaptic weights of the network are stored in a continuously tunable photoresponsivity matrix. The sensor can itself constitute an ANN that can simultaneously sense and process optical images without latency. They […]

Highly sensitive sensors show promise in enhancing human touch

Nanowerk  February 18, 2020 People rely on a highly tuned sense of touch to manipulate objects, but injuries to the skin and the simple act of wearing gloves can impair this ability. Researchers in China have developed a visually aided tactile enhancement system for precise motion control by combining ultrathin, highly sensitive, crack-based strain sensors and signal acquisition circuit with real-time display equipment. With the optimization of the thicknesses of the substrates and sensitive films of the strain sensors, the device has a detection limit as low as 0.01% and an ultrahigh gauge factor of 44 013 at a strain of […]

A spookily good sensor

Phys.org  February 19, 2020 Researchers in Japan placed a millimeter-sized sphere of yttrium iron garnet in the same resonant cavity as a superconducting Josephson junction qubit, which acted as the sensor. Because of the coupling of the sphere to resonant cavity, and, in turn, between the cavity to the qubit, the qubit could only be excited by an electromagnetic pulse if no magnetic excitations were present in the sphere. Reading the state of the qubit then reveals the state of the sphere. By using single-shot detection instead of averaging, they were able to make the device both highly sensitive and […]

Smaller detection device effective for nuclear treaty verification, archaeology digs

Phys.org  January 29, 2020 Researchers at MIT describe the Monte Carlo (MC) based design of a compact epithermal Neutron Resonance Transmission Analysis (NRTA) radiographic instrument, which uses a moderated, compact deuterium-tritium neutron source and an epithermal neutron detector. The MC simulations presented in this work demonstrate accurate time-of-flight reconstructions for transmitted neutron energies, capable of differentiating isotopic compositions of nuclear material with high levels of accuracy. A new generation of miniaturized neutron sources will allow this technique to achieve measurements with greater precision and speed, with significant impact on a variety of engineering and societal problems. The instrument would have […]

Molecular Electronics Chip With 100 Million DNA Reading Devices

Next Big Future  December 30, 2019 Utilizing advances in semiconductor technology, nano-fabrication and bio-sensors, a company in America has created standard CMOS chips that directly integrate sensor molecules into the CMOS integrated circuits. The current chip is designed to read DNA; future chips will be designed for protein detection and other diverse bio-sensing applications. It reduces whole genome sequencing from days to minutes, through direct electrical sensing delivered at the speed of natural DNA synthesis. Using a single molecule workflow eliminates the time and complexity of sample preparation, delivering ultimate simplicity, speed and lower costs. This also improves the data […]

A fast and inexpensive device to capture and identify viruses

EurekAlert  December 23, 2019 Currently, virologists estimate that 1.67 million unknown viruses are in animals, a number of which can be transmitted to humans. A team of researchers in the US (Pennsylvania State University, New York University) synthesized a gradient of aligned carbon nanotube forest arrays to capture different viruses and detect them in-situ Raman spectroscopy to identify the viruses based on their individual vibration. They designed and assembled a portable platform that enriches virus particles from several milliliters of clinical samples in a couple of minutes. They added gold nanoparticles to enhance the Raman signal to detect the virus […]

Mathematicians propose new design for wireless nanosensory networks

Phys.org  December 17, 2019 An international team of researchers (Finland, Russia) has developed a new method for collecting data from passive wireless nanosensors using devices which can measure the parameters of objects and convert them into a signal. They use microscopic nanoelements and do not have an integral battery pack. They do not require any maintenance, have a long service life and low cost. Mathematicians have modeled an experiment with gateways, which are made on the basis of unmanned aircraft. THz frequency range is used for the wireless energy transfer to nanodevices as well as for communication with them. The […]

Thunderquakes make underground fiber optic telecommunications cables hum

Science Daily  December 11, 2019 Researchers at Pennsylvania State University report on a distributed acoustic sensing (DAS) array using preexisting underground fiber optics beneath the Penn State campus for detecting and characterizing thunder‐induced ground motions. During a half‐hour interval in State College, PA, they identified 18 thunder‐induced seismic events in the DAS array data. The high‐fidelity DAS data show that the thunder‐induced seismic are very broadband, with their peak frequency ranging from 20 to 130 Hz. The dense DAS data enable them to simulate thunder‐seismic wave propagation and full waveform synthetics and further locate the thunder‐seismic source by time‐reversal migration. […]