Antibody-functionalized, Au-gated AlGaN∕GaN high electron mobility transistors (HEMTs) were used to detect botulinum toxin. The antibody was anchored to the gate area through immobilized thioglycolic acid. The AlGaN∕GaN HEMT drain-source current showed a rapid response of less than 5s when the target toxin in a buffer was added to the antibody-immobilized surface. We could detect a range of concentrations from 1to10ng∕ml. These results clearly demonstrate the promise of field-deployable electronic biological sensors based on AlGaN∕GaN HEMTs for botulinum toxin detection.

There has been significant recent interest in the use of surface-functionalized thin film and nanowire wide bandgap semiconductors, principally GaN, InN, ZnO and SiC, for sensing of gases, heavy metals, UV photons and biological molecules. For the detection of gases such as hydrogen, the semiconductors are typically coated with a catalyst metal such as Pd or Pt to increase the detection sensitivity at room temperature. Functionalizing the surface with oxides, polymers and nitrides is also useful in enhancing the detection sensitivity for gases and ionic solutions. The wide energy bandgap of these materials make them ideal for solar-blind UV detection, which can be of use for detecting fluorescence from biotoxins. The use of enzymes or adsorbed antibody layers on the semiconductor surface leads to highly specific detection of a broad range of antigens of interest in the medical and homeland security fields. We give examples of recent work showing sensitive detection of glucose, lactic acid, prostate cancer and breast cancer markers and the integration of the sensors with wireless data transmission systems to achieve robust, portable sensors.

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Achieving high‐performance luminescence for underwater bonding remains a significant challenge in materials science. This study addresses this issue by synthesizing a luminescent material based on an aggregation‐induced emission (AIE) monomer and copolymerizing it with lipoic acid (LA) to create an AIE supramolecular polymer. The resulting copolymer exhibits strong fluorescence under ultraviolet (UV) irradiation at 365 nm due to the AIE of TPEE and enables underwater adhesion. The P(LA‐TPEE) polymer demonstrates potential for digital encryption and decryption of quick response (QR) codes underwater. Furthermore, it can dissolve well in anhydrous ethanol, producing an environment‐friendly and super waterproof adhesive. Most notably, the P(LA‐TPEE) solution can be sprayed on human skin, creating an invisible tattoo that only became visible under UV light due to the hydrogen bond (H‐bond) and π–π structures. This smart tattoo can be quickly wiped away with alcohol, avoiding the painful and harmful process of tattoo removal. It can also be repeatedly applied to draw the preferred tattoo pattern. This AIE supramolecular polymer shows great potential in underwater adhesion and repair, underwater message encryption, and non‐toxic and painless invisible tattooing. Overall, this study provides a valuable approach for material design in the future.

In 0.52 Al 0.48 As ∕ In 0.39 Ga 0.61 As 0.77 Sb 0.23 ∕ In 0.53 Ga 0.47 As double heterojunction bipolar transistors (DHBTs) were irradiated with 5MeV protons at fluences from 2×1011to2×1015protons∕cm2. The radiation produced significant increases in generation-recombination leakage current in both emitter-base and base-collector junctions. The DHBTs irradiated with a dose of 2×1011cm−2, which was equivalent to around 40years of exposure in low Earth orbit, showed minimal changes in the junction ideality factor, generation-recombination leakage current, current gain, and output conductance. The InAlAs∕InGaAsSb∕InGaAs DHBTs appear to be well suited to space or nuclear industry applications.