# SPR biosensor with a graphene overlayer for carcinoma detection

## TL;DR

This paper presents a new SPR biosensor design with graphene that improves sensitivity for detecting carcinoma biomarkers.

## Contribution

A novel SPR biosensor architecture with graphene overlayer is proposed, showing enhanced sensitivity and detection accuracy.

## Key findings

- The CaF2/Cu/TiO2/Graphene stack achieved 481.29°/RIU sensitivity and DA = 0.80.
- The graphene-integrated design outperformed TiO2-only and Cu-only baselines in detection performance.
- The design enables cost-effective and sensitive carcinoma biomarker detection.

## Abstract

Early carcinoma detection benefits from label-free, high-sensitivity surface plasmon resonance (SPR) biosensors. We computationally evaluated multilayer SPR architectures based on CaF2/Cu/TiO2/Graphene using the transfer-matrix method at 633 nm. Across 1–5 ng/mL, we analyzed reflectance, resonance-angle shifts, and near-field profiles, and derived sensitivity, detection accuracy (DA), figure of merit, and the limit of detection (LOD). The CaF2/Cu/TiO2/Graphene stack yielded the best performance, achieving 481.29°/RIU sensitivity and DA = 0.80, with pronounced evanescent-field confinement at the sensing interface. Under identical modeling conditions, this graphene-integrated configuration outperformed TiO2-only and Cu-only baselines within the studied range. These results indicate a cost-effective platform for sensitive carcinoma biomarker detection. Calculation details for LOD and other metrics are provided in Methods, and practical considerations for experimental realization are discussed.