A Novel Mxene-SPR-Based Sensor for Sensing Different Types of Cancers

Talia Tene^1*Yesenia Cevallos^2,3Paola Gabriela Vinueza Naranjo^2,4Deysi Inca²Marcelo León⁵Said Boukerche⁶Cristian Vacacela Gomez⁷

• ¹Universidad Técnica Particular de Loja, Loja, Ecuador
• ²National University of Chimborazo, Riobamba, Chimborazo, Ecuador
• ³Universidad San Francisco de Quito, Quito, Pichincha, Ecuador
• ⁴University of the Americas, Quito, Pichincha, Ecuador
• ⁵Universidad Tecnológica Ecotec, Guayaquil, Guayas, Ecuador
• ⁶Mohamed-Cherif Messaadia University, Souk Ahras, Algeria
• ⁷National Laboratory of Frascati (INFN), Frascati, Italy

Early-stage cancer screening benefits from optical transducers capable of reading minute refractive-index deviations in biofluids. This work models a surface-plasmon-resonance (SPR) biosensor that stacks copper, silicon nitride, and MXene in Kretschmann geometry and evaluates its response to six tumour-related refractive-index increments (Δn = 0.014-0.024 RIU). Transfer-matrix calculations guide a layer-by-layer optimisation: 40 nm Cu, 7 nm Si₃N₄, and two MXene sheets form the best-balanced configuration (Sys₃), while a single MXene layer on 45 nm Cu (Sys₄) offers an alternative with lower optical loss. The optimised MXene sensors raise angular sensitivity to 254 ° RIU⁻¹ (Sys₃) and 312 ° RIU⁻¹ (Sys₄) for the breast-T2 model, more than doubling the response of a dielectric-only stack and approaching values reported for multi-metal reference designs. Quality factors range from 48 to 58 RIU⁻¹ in Sys₄ and 30 to 35 RIU⁻¹ in Sys₃, corresponding detection limits fall near 2 × 10⁻⁵ RIU, sufficient to resolve the smallest Δn in the cancer panel. Optical loss remains below nine per cent in Sys₃ and under eight per cent in Sys₄, preserving reflected-intensity contrast for angle tracking. These results indicate that a copper platform augmented with sub-nanometre MXene and a thin Si₃N₄ spacer can match state-of-the-art sensitivity while relying on a single plasmonic metal and low-temperature fabrication. The study is purely theoretical and uses bulk refractive-index shifts as the sensing mechanism, future work should address surface chemistry, fabrication tolerances, and clinical validation.