A multiple cancer cell optical biosensing metastructure realized by CPA.

A one-dimensional optical biosensing metastructure (OBM) with graphene layers is presented in this paper. It is realized by coherent perfect absorption (CPA) and operates in the transverse electric mode. It shows a strong linear fitting relationship between the refractive index (RI) of the analysis layer and the frequency corresponding to the absorption peak, and the R-square is up to 1. Additionally, based on the principle of CPA, the OBM can realize the function of multiple cancer cell detection by adjusting the detection range by controlling the phase difference of coherent electromagnetic waves. Its detection ranges are 1.34-1.355 and 1.658-1.662. Thanks to its high-quality factor, great figure of merit, and low detection limit, whose best values are, respectively, 6.9 × 104, 1.2 × 104 RIU-1, and 3.6 × 10-6 RIU, the detection of weak changes in the RI of a cancer cell is possible. Additionally, its sensitivity can reach 26.57 THz RIU-1. This OBM based on CPA has major implications for advancing the study and investigation into the application of CPA. It also provides a simple and efficient approach to distinguish cancer cells and may be widely used in the biomedical field.

High sensitivity multitasking non-reciprocity sensor using the photonic spin Hall effect.

A non-reciprocity sensor based on a layered structure with multitasking is proposed, which realizes biological detection and angle sensing. Through an asymmetrical arrangement of different dielectrics, the sensor obtains non-reciprocity on the forward and backward scales, thus achieving multi-scale sensing in different measurement ranges. The structure sets the analysis layer. Injecting the analyte into the analysis layers by locating the peak value of the photonic spin Hall effect (PSHE) displacement, cancer cells can accurately be distinguished from normal cells via refractive index (RI) detection on the forward scale. The measurement range is 1.569∼1.662, and the sensitivity (S) is 2.97 × 10-2 m/RIU. On the backward scale, the sensor is able to detect glucose solution with 0∼400 g/L concentrations (RI = 1.3323∼1.38), with S = 1.16 × 10-3 m/RIU. When the analysis layers are filled with air, high-precision angle sensing can be achieved in the terahertz range by locating the incident angle of the PSHE displacement peak; 30°âˆ¼45°, and 50°âˆ¼65° are the detection ranges, and the highest S can reach 0.032 THz/°. This sensor contributes to detecting cancer cells and biomedical blood glucose and offers a new way to the angle sensing.