Nanoplasmonic biosensors: current perspectives

Abstract

Recent advances in nanotechnology and nanofabrication have helped develop a wide variety of nanostructured platforms for use as nanoplasmonic biosensors. These can either be in solution phase or be confined on a substrate in the form of metallic nanofilms or periodic arrays. Plasmonic properties of these nanostructures depend on the size, shape, position, orientation, etc, and can be altered by interaction between probe and target species on the metal surfaces. This property of nanostructures has been exploited in refractometric nanoplasmonic biosensors, surface-enhanced Raman spectroscopy-based biosensors, plasmon-enhanced fluorescence biosensors, etc. These nanoplasmonic biosensors are employed in diverse areas such as clinical diagnosis, biosecurity, food, and environmental monitoring. Among these, clinical diagnosis has attracted the most research and commercial interest. Nanoplasmonic biosensors can detect disease biomarkers using highly specific and selective biological recognition elements on the nanostructured surfaces. Many excellent reviews exist in this area that trace the developments over the past 3 decades. This review focuses on some of the more recent studies on the detection of various disease biomarkers through nanoplasmonic biosensors. In the process, we have described fabrication techniques and biofunctionalization of such biosensors.