Design, Characterization, and Integration of Nanometric Objects with Chip-scale Platforms for Disease Diagnosis

Abstract

Nanomaterials (e.g., metal nanoparticles) are playing increasingly important roles in disease detection. This emergence arises from the need to detect markers and pathogens at ever-lower levels in human and veterinary diagnostics, homeland security, and food and water. This paper reviews our recent work using surface enhanced Raman scattering for detection of proteins, viruses, and microorganisms in heterogeneous immunoassays. It describes the assay platform, which consists of an antibody-modified capture substrate and gold nanoparticle-based label. The latter draws on the ability to reproducibly construct gold nanoparticles modified with a monolayer of an intrinsically strong Raman scatterer that is coated with a layer of antibodies. This construct, referred to as an extrinsic Raman label, exploits both the signal enhancement of scatterers when coated on nanometer-sized gold particles and the antigenic binding specificity of the immobilized antibody layer. Issues related to nonspecific adsorption, particle stability, and measurement reproducibility are also discussed.

Prospects for point-of-care pathogen diagnostics using surface-enhanced Raman scattering (SERS)

“…30 Since its discovery in the late 1970's, [31][32][33] SERS has been applied to a wide range of measurements in analytical and biological chemistry. 23,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48] Vo-Dinh and co-workers were the first to report on the potential of SERS as a spectrochemical methodology in 1984. 49 Not long thereafter, Cotton and colleagues described an approach to apply SERS to immunoassays.…”

“…49 Not long thereafter, Cotton and colleagues described an approach to apply SERS to immunoassays. 34 Indeed, SERS-based immunoassays have become widespread, 23,[34][35][36][37]39,42,44,45,47,48 and this review is structured to discuss its use for pathogen detection and its potential in point-of-care (POC) applications. This review therefore: (1) examines the strengths and weaknesses of today's diagnostic tests for pathogens; (2) highlights a few of the many exciting developments demonstrating the potential of SERS in pathogen detection; and (3) discusses obstacles faced when attempting to move SERS-based diagnostic tests from the laboratory to field applications.…”