Applications and Recent Trends in Surface Acoustic Wave Biosensors

This chapter presents the most relevant applications of surface acoustic wave (SAW) biosensors published between 2019 and the beginning of 2023. These recent studies showed that besides quantifying several types of proteins and detecting bacteria and viruses, SAW biosensors can access cells’ viscous/elastic properties and their adhesion/growth/detachment processes. Numerous functionalization methods are presented, from the most common ones, such as self-assembled layers and molecularly imprinted polymers, to sophisticated ones, such as sandwich structures incorporating doped nanoparticles (NP) or NP-decorated graphene tubes. In this chapter, we also present new trends in SAW biosensors. Two routes can be used separately or simultaneously: using new multi-layered piezoelectric materials with high coupling coefficients and/or high acoustic wave velocities and new geometries of interdigital transducers (IDTs). This chapter finally puts forward the interest of multi-transduction to access multiparametric response accurately and fully characterize analytes in complex media. It highlights the potential of biosensors to address different public health and to accompany the current trends toward detecting increasingly small biological entities.