Emerging use of nanostructure films containing capped gold nanoparticles in biosensors

Jitendra Satija¹, Reshma Bharadwaj², VVR Sai³, Soumyo Mukherji^1,2,4

¹Department of Bioscience and Bioengineering, IIT Bombay, Mumbai,Maharashtra, India; ²Centre of Excellence for Nanoelectronics, IIT Bombay, Mumbai, Maharashtra, India; ³Department of Chemistry, University of Idaho, Moscow, ID, USA; ⁴Centre for Research in Nanotechnology and Sciences, IIT Bombay, Mumbai, Maharashtra, India

Abstract: The localized surface plasmon resonance (LSPR) property of gold nanoparticles (GNP) has been exploited in a variety of optical sensor configurations including solution-based bioassays, paper-based colorimetric detection, surface-confined nanoparticle film/array-based sensing, etc. Amongst these, gold nanostructured films are of great interest because of their high stability, good reproducibility, robustness, and cost-effectiveness. The inherent optical characteristics of GNP, are attributed to parameters like size and shape (eg, nanospheres, nanorods, nanostars), eg, LSPR spectral location sensitivity to the local environment, composition (eg, gold–silver or silica–gold nanoshells), sensing volume, mesospacing, and multiplexing. These properties allow sensor tunability, enabling enhanced sensitivity and better performance of these biosensors. Ultrasensitive biosensor designs were realized using gold nanostructured films fabricated by bottom-up as well as top-down approaches. In this review, we describe the past, present, and future trends in the development of GNP-LSPRbased sensors, concentrating on both design (fabrication) and application. In the process, we have discussed various combinations of GNP size and shape, substrate, and application domains.

Keywords: localized surface plasmon resonance, gold nanoparticles, label-free optical biosensor