Graphene assisted multilayer SPR biosensor with superior specificity for breast cancer cell detection

• A new biosensor has been developed that uses Strontium Titanate and Graphene nanomaterials to quickly and accurately detect Breast Cancer. • The sensor allows for thorough detection of MCF-7 & MDA-MB-231 • Superior performance characteristics are indicated by the suggested SPR biosensor's significantly increased sensitivity, higher figure of merit (FoM), and achieved minimum reflectivity. • These findings demonstrate the sensor's improved diagnostic potential and its potential applicability for precise and trustworthy breast cancer detection. Early detection of breast cancer cells is the most significant factor for patient outcome and treatment strategies. A highly sensitive surface plasmon resonance (SPR) biosensor is designed with the ability to recognize two common breast cancer cells MCF-7 and MDA-MB-231 from their refractive index signals. The sensor is a Kretschmann configuration and consists of an N-FK51A prism covered with multilayer ZnO/Cu/SrTiO 3 /Graphene. These layers are chosen and optimized to help in strong plasmon excitation, increased optical confinement and improved field interaction at the sensing interface. Optical characteristics of the proposed structure are analyzed with the transfer matrix method (TMM) combined with angular interrogation for a wavelength of 633 nm. For further verification of its performance, Finite Element Method (FEM) and Finite Difference Time Domain (FDTD) simulations are conducted to assess its electromagnetic and mechanical characteristics. The multilayered structure provides a clear shift in the resonance with small changes in refractive index for both cell types and demonstrates high sensitivity within the bio-refractive index range. The sensor presents sensitivities of 396.28 deg/RIU for MCF-7 and 354.35 deg/RIU for MDA-MB-231. The corresponding quality factors (QF) are 94.15 RIU -1 and 89.64 RIU -1 and FoM values are up to 87.61 and 88.63 respectively. The biosensor also demonstrate remarkable accuracy of detection (DA) of 0.237 deg -1 for MCF-7 and 0.253 deg -1 for MDA-MB-231 with excellent precision and reliable resonance features. Therefore, the N-FK51A/ZnO/Cu/SrTiO 3 /Graphene based SPR biosensor shows a good detecting ability and optical stability in general.