Investigating angiotensin converting enzyme-2 and SARS CoV-2 spike protein interactions using a combined label-free and fluorescence detection approach

The emergence of Coronavirus Disease in 2019, driven by the novel pathogen SARS-CoV 2, has posed a profound challenge to global health. In this context, we employed a combined label-free and fluorescence-based approach to investigate the interaction between two forms of the SARS-CoV-2 spike protein: the receptor-binding domain and the trimeric form. This study utilized one-dimensional photonic crystals supporting Bloch surface waves as optical biosensors. Through the analysis of label-free signals from spike protein probes and ACE-2 molecules, crucial data were gathered, including surface mass coverage and molecular density. The adaptability of this method holds great potential for advancing diagnostic tools and enhancing the understanding of disease biomarkers. These findings provide novel insights into the molecular interactions at the core of the COVID-19 pandemic, deepening our knowledge on the receptor-binding processes involved during SARS-CoV-2 outbreak.