In this work, we developed a gold nanoparticle functionalized AlGaN/GaN HEMT sensor for fast and ultrasensitive detection of TNT. This HEMT sensor showed attractive properties for TNT detection in terms of speed, sensitivity and miniaturization.

Underwater wireless optical communication (UWOC) is a wireless communication technology using visible light to transmit data in an underwater environment, which has wide applications. Based on lift-off (In,Ga)N nanowires, this work has proposed and successfully demonstrated a self-powered photoelectrochemical (PEC) photodetector (PD) with excellent transmissivity. The transparent functionality of the PD is critical for 360° omnidirectional underwater detection, which was realized by detaching the (In,Ga)N nanowires from the opaque epitaxial substrates to the indium tin oxide (ITO)/glass. It was also found that the insulating SiO₂ layer can enhance the photocurrent by about 12 times. The core–shell structure of the nanowires is beneficial for generating carriers and contributing to the photocurrent. Furthermore, a communication system with ASCII code is set to demonstrate the PD detection in underwater communication. This work paves an effective way to develop 360° omnidirectional PDs for the wide applications in UWOC system and underwater photodetection.

Herein, an extended gate-AlGaN/GaN high electron mobility transistor (EG-AlGaN/GaN HEMT) with a high sensitivity for bioassay has been developed. The major difference between the EG-AlGaN/GaN HEMT transducer and a traditional AlGaN/GaN HEMT transducer is the sensing region. By extending the gate electrode and separating the sensing region from the channel of the AlGaN/GaN HEMT, our EG-AlGaN/GaN HEMT has a much larger sensing area and therefore achieves a low limit of detection (0.1 pg mL⁻¹). Additionally, our transducer exhibits excellent linearity (R² = 0.9934) with a wide range (from 0.1 pg mL⁻¹ to 100 ng mL⁻¹). We also demonstrate that the larger area of the extended sensing region can provide a larger current response of the transducer. The results give a proof-of-concept demonstration of the utilization of the EG-AlGaN/GaN HEMT for trace-level biological detection.

Structured light projection provides a promising approach to achieving fast and non‐contact three‐dimensional (3D) imaging. The resolution is a crucial index that represents security and accuracy in applications such as face recognition and robot vision. It depends on the density of dots in the projection. However, further improving the density of dots in the current system must be at the cost of speed or volume. Here, an all‐dielectric ultra‐thin metasurface is designed and fabricated to project a multi‐wavelength dot array. The density of dots is improved because projected dots with different wavelengths fill the gaps with each other. The experimental results demonstrate that the multi‐wavelength projection improves the resolution of 3D imaging. Furthermore, the multi‐wavelength system is beneficial to measuring a surface with varying colors. The approach has the potential to achieve a new generation of high‐resolution systems for tiny fluctuations and colorful 3D imaging in dark environments.

A molecular gated-AlGaN/GaN high electron mobility transistor has been developed for pH detection.

In this letter, we propose a highly reliable biosensor based on the disposable gate (DG) AlGaN/GaN high-electron mobility transistor (HEMT) sensor. The greatest advantage of this device is that the HEMT structure and the sensing structure containing the sensitive membrane are separate, overcoming the drawback of being easily contaminated in a biochemical environment. The DG structure HEMT sensor exhibited stable and rapid response to the addition of different concentrations of the prostate-specific antigen (PSA), and the achieved limit of PSA detection was as low as 100 fg/mL. It was also found that the DG AlGaN/GaN HEMT sensor shows good linearity and specificity. These results demonstrate the DG HEMT sensor can be considered to be a promising biosensor platform for practical application in disease diagnosis.