Author(s): Pereira, Ana Cláudia Santos ; Sousa, Cristina ; Mateus, Daniela ; Sebastião, Ana Isabel ; Cruz, Maria Teresa ; Mato, Ana Miguel ; Moreira, Felismina
Date: 2025
Persistent ID: https://hdl.handle.net/1822/94813
Origin: RepositóriUM - Universidade do Minho
Subject(s): Colorimetric; COVID-19 immunity; Paper-based sensor; Virus-like particles
The COVID-19 pandemic has driven immunity acquisition through infection or vaccination, leading to SARS-CoV-2 antibodies. This study introduces a colorimetric biosensor for COVID-19 immunity screening using Virus-Like Particles (VLPs) with SARS-CoV-2 spike protein motifs on a cellulose carrier. The cellulose was chemically modified with DSS to secure the VLPs, verified via FTIR. Detection utilized the Bradford reagent, with RGB color analysis via ImageJ and smartphone images. The test strips demonstrated high sensitivity (R > 0.998) across a 1040 µg/mL range in buffer and serum, with 30-minute incubation. They also exhibited selectivity against interferents like albumin, glucose, and urea. Success with undiluted samples highlights clinical potential. This broad-spectrum, REASSURED-compliant method is promising for global testing applications. © 2025 The Author(s)
