Rational design and analysis of SPR biosensor based on Ag/AlN/BlueP-MoS₂/BP heterostructure for ultrasensitive detection of basal cell carcinoma

Skin cancer is one of the most commonly occurring malignancies in the world whereby the abnormal development of the skin cells is achieved through lack of control, most frequently through long exposure to ultraviolet (UV) radiations. Timely and precise results are essential towards better treatment outcomes and patient survival rates. This study describes the design and mathematical modelling of an extremely sensitive surface plasmon resonance (SPR) biosensor for the detection of skin cancer-related biomarkers of Basal Cell Carcinoma (BCC). The envisioned design of the multilayer SPR sensor is based on the following layers: BK7 glass substrate, silver (Ag) plasmonic layer, aluminum nitride (AlN) dielectric layer, and composite of 2D-materials, blue phosphorene/Molybdenum Disulfide (BlueP/MoS 2 ), and Black phosphorus (BP). The sensor performance was measured by means of numerical modeling in the Transfer Matrix Method (TMM) at the wavelength of 633 nm that is generally chosen in SPR analysis due to its high sensitivity. The numerical sensing response was evaluated using RI values of 1.360 and 1.380 to represent the modeled normal skin and BCC skin sensing conditions. The optimized setup showed a high sensitivity of 352.27 °/RIU and a quality factor of 93.41 RIU⁻¹ , indicating that it was highly sensitive and demonstrating the potential of the proposed structure for RI-based BCC sensing. In this study, we found that the proposed SPR biosensor can provide an effective pathway for the noninvasive clinical examination of skin cancer. The integration of 2D materials into conventional plasmonic structures presents novel possibilities to the next-generation diagnostic platforms that can have a positive impact on a broad medical and environmental sensing scope.