Hydrogel Plasmonic Nanocomposites for Biosensing Applications: Numerical Modeling and Transduction Mechanisms

In recent times, there has been significant progress in the field of flexible plasmonic sensors, driven by the numerous advantages offered by flexible sensors, particularly their mechanical properties and ability to conform to non-planar surfaces. Taking advantage of these benefits, a three-dimensional (3D) optical sensor has been developed by integrating gold citrate nanoparticles into a polymer matrix, specifically a polyethylene glycol diacrylate (PEGDA) hydrogel. This hybrid sensor exhibits the ability to detect molecules through both label-free and non-label-free approaches, leveraging the unique characteristics of hydrogels and the presence of noble metal nanoparticles. The mechanical properties of hydrogels allow for expansion or swelling in the presence of water, enabling sensitive detection of analytes. Additionally, the integration of noble metal nanoparticles, such as gold citrate nanoparticles, offers enhanced sensing capabilities through mechanisms such as metal-enhanced fluorescence (MEF) and surface-enhanced Raman scattering (SERS). The proposed sensor platforms are not only effective but also cost-efficient, making them suitable for large-scale industrial production. Furthermore, they possess low detection limits, indicating their high sensitivity in detecting target molecules. With these promising features, the 3D optical sensor holds great potential for future applications in various fields, ranging from healthcare diagnostics to environmental monitoring and beyond. The scalability and versatility of these platforms pave the way for a wide range of practical applications in the years to come.