Multichannel Biosensor for Skin Type Analysis

Skin cancer is the uncontrolled growth of abnormal skin cells, and it may occur due to unrepaired DNA damage to skin cells; some of the common types are squamous cell carcinoma, basal cell carcinoma, melanoma. Squamous cell carcinoma is a type of cancer caused by an uncontrolled growth of abnormal squamous cells. Basal cells produce new skin cells as old ones die. Limiting sun exposure can help prevent these cells from becoming cancerous. The first step toward skin cancer detection is to asses skin type. Photonic crystal (PhC) is a periodic optical nanostructure used in the current work as a biosensor. PhC exhibits optical band gaps which are used for super-prisms, negative refraction, and dispersion compensation. We have created a biosensor with three sensing holes or point defects in PhC. The designed biosensor can sense three refractive indices simultaneously. By changing the properties of the sensing hole, the wavelength shifts and new resonant wavelength can be observed. Using a square lattice structure, we can distinguish between various sensing levels concerning amplitude and different wavelength values for all the three types of skin, namely Asian, Dark, and Caucasian skins. When the nano-sensing hole size is 0.22 um, the result shows a distinctly separable wavelength shift. When the sensing hole size decreases, then we cannot distinguish between Dark and Asian skin as the content of the melanin pigment present is more. We could conclude from the simulation that the designed biosensor can be used as a multichannel biosensor for skin type analysis.