This work presents an innovative magnetoelastic (ME) biosensor using graphene functionalized with the SARS-CoV-2 N protein for antibody detection via magnetoelastic resonance. Graphene was chosen for its biocompatibility and high surface area, enabling efficient antigen adsorption, validated by techniques such as energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and micro-Raman spectroscopy. Changes in Raman bands (a ∼10cm−1 shift in the 2D band and an increase in the ID/IG ratio from 0.03 to 0.60) confirmed non-covalent interactions and enhanced surface coverage with ~100 μg of N protein. Tests using human plasma (10 RT-PCR-positive and 10 negative samples) demonstrated a clear distinction between groups using graphene sensors functionalized with ~100 μg of N protein. Enzyme-linked immunosorbent assay (ELISA) validation corroborated the results. Optimization of protein concentration and biofunctionalization time highlighted the importance of homogeneous surface coverage for reproducibility of the graphene-based ME biosensor. The platform combines graphene's advantages with the wireless, real-time detection capabilities of ME sensors, offering low cost, high sensitivity, and potential for automation, with applications in point-of-care diagnostics.
@article{arxiv.2505.08039,
title = {Graphene-based magnetoelastic biosensor for COVID-19 serodiagnosis},
author = {Wenderson R. F. Silva and Larissa C. P. Monteiro and Murilo C. Costa and Renato V. A. Boaventura and Eduardo N. D. de Araújo and Rafael O. R. R. Cunha and Tiago A. de O. Mendes and Rodrigo G. Lacerda and Joaquim B. S. Mendes},
journal= {arXiv preprint arXiv:2505.08039},
year = {2025}
}