Nanoparticle-based lateral flow assays

Lateral flow assays (LFAs) are paper-based analytical devices that allow for the performance of in situ diagnostic tests with good sensitivity, specificity, repeatability and low limit of detection. The application of different kinds of nanoparticles with different properties have made LFAs compatible with different detection methods (e.g. colorimetry, photoluminescence, magnetism, heating, electroactivity), thus showing their versatility. Even though LFA technology is well-established, research on the topic is more alive than ever due to the advances in the study of nanomaterials, the implementation of smartphone technology for signal readout and the creativity in finding new strategies for signal enhancement. In this chapter, the applications of LFAs using different kind of nanoparticles as labels are compiled, demonstrating their use in a range of fields such as clinical diagnostics, environmental monitoring, food safety and veterinary. Given the relevance of nanoparticles in the performance of LFAs, a section of the chapter is dedicated to biofunctionalisation strategies.