Real-time topography inspection of DPPC monolayers using a surface-plasmon resonance sensor

This paper presents an alternative optical characterization of biosensors based on supported lipid monolayers (SLMs). Developing these biosensors requires precise thickness characterization of the films to understand their structure and dynamics. This paper proposes an optical technique to measure the thickness, optical properties, and location of a dipalmitoyl-phosphatidylcholine (DPPC) SLM on top of a metallic thin film. DPPC SLMs are of interest for biosensing applications, such as detecting pulmonary-related infections like SARS-CoV-2, Avian Influenza, and the H1N1 influenza virus. The monolayer was fabricated using the Langmuir–Blodgett technique, and the experimental characterization consisted of measuring the surface-plasmon resonance angle in the Kretschmann configuration. This technique provides an alternative option for real-time visual inspection and determination of the location and shape of DPPC monolayers in large areas. Therefore, it offers a useful tool for further developing SLM-based biosensors.