Nanostructures as analytical tools in bioassays

Abstract

We critically evaluate the usefulness of different nanostructures described as labels, nanoscaffolds or separation media in immunoassays and nucleic-acid hybridization assays. Many of the great number of publications describe only theoretical aspects of using these nanostructures or nanoparticles, but do not verify their applicability in the presence of potential interferents that can be present in the sample matrix. We attempt a systematic study of the advantages and the limitations of using these new reagents in bioassays, the different assay formats for individual and multiplexed detection, and the capability of these assays in analyzing real samples.

Keywords: Immunoassay; Individual assay; Multiplexed assay; Nanoparticle; Nucleic acid.

Figure 1

Distribution and number of publications per year involving the use of different nanoparticles (NPs) in immunoassays and hybridization assays. (Period: 1995–2007; Source: Scifinder Scholar).

Figure 2

General scheme of microsphere-based and metal-nanowire barcodes. A,B and C correspond to different encoded microspheres. 1, 2, 3: molecular recognition elements, such as capture antibody or nucleic-acid strand. 1′, 3′: analytes. 1″-•, 2″-• and 3″-•, and 1″-•, 2″-• and 3″-• are NP-labeled antibodies or labeled complementary nucleic-acid strands.