Search

Advanced biosensors must exhibit high sensitivity, reliability, and convenience, making them suitable for detecting trace samples in biological or medical applications. Currently, biometric identification is the predominant method in clinical practice, but it is complex and time-consuming. In this study, we propose an optical metasurface utilizing the Fano resonance effect, which exhibits a sharp resonance with a transmittance of 32% at 0.65 THz. The resonance dip has a narrow bandwidth of 0.07 THz and a high Q-factor of 42. This resonance arises from the coupling of bright and dark modes, underpinned by the electromagnetic mechanism of Fano resonance. We integrated the metasurface into a microfluidic platform and fabricated low-temperature gallium arsenide photoconductive antennas (LT-GaAs-PCAs) on both sides of the microfluidics to efficiently generate and detect THz waves, significantly reducing the system’s volume. The biosensor’s detection limits for Escherichia coli(E. coli) and cefamandole nafate are 5 × 103cells/mL and 5 μg/mL, respectively. Experimentally, when E. coliand cefamandole nafate solutions were sequentially injected into the microfluidic chip, a blue shift in the spectrum was observed. The sensor measured a 95.2% killing rate of E. coliby 40 μg/mL cefamandole nafate solution, with only a 3% deviation from biological experiments. Additionally, a timed killing experiment using 40 μg/mL cefamandole nafate on E. colirevealed a 93.7% killing rate within 3 min. This research presents a THz microfluidic biosensor with rapid detection, high sensitivity, and enhanced portability and integration, offering a promising approach for biomedical research, including antibiotic efficacy assessment and bacterial concentration monitoring.

MicroRNAs (miRNA) have been shown to be associated with tumor diagnosis, prognosis, and therapeutic response. MiR-328-3p plays a significant role in breast cancer growth; however, its actual function and how it modulates specific biological functions is poorly understood. Here, miR-328-3p was significantly downregulated in breast cancer, especially in patients with metastasis. Mitochondrial carnitine palmitoyl transferase 1a (CPT1A) is a downstream target gene in the miR-328-3p-regulated pathway. Furthermore, the miR-328-3p/CPT1A/fatty acid β-oxidation/stemness axis was shown responsible for breast cancer metastasis. Collectively, this study revealed that miR-328-3p is a potential therapeutic target for the treatment of breast cancer patients with metastasis, and also a model for the miRNA-fatty acid β-oxidation-stemness axis, which may assist inunderstanding the cancer stem cell signaling functions of miRNA.

We designed a linear polarization converter based on metasurface and simulated its functionality. It has a broad bandwidth and operates in the terahertz frequency range (0.4–1.2 THz). The polarization converter consists of a polyimide substrate, a metal grating and a bimetallic split ring resonator. In a bimetallic split ring resonator, the gaps between the rings are rotated by 90° from one another. The structure is simulated by commercial software CST STUDIO SUITE. The results show that the device successfully converts the polarization of terahertz wave from yto x. This structure also has high stability in terms of incidence angle and operates efficiently in the range of 0° to 45°.This kind of polarization converter has a wide application prospect in satellite communication, radar detection, 3D imaging of displays, and other fields.