Improving Colorimetric Assays through Protein Enzyme-Assisted Gold Nanoparticle Amplification

• DOI: 10.1021/ar300044j
• Publication Date: 2012-07-11T12:42:15Z
• Authors: Xiaoji Xie; Wei Xu; Xiaogang Liu
• Keywords: Nanomaterials; Rational design

The discovery of the DNA-mediated assembly gold nanoparticles was a great moment in history science; this understanding and chemical control enabled rational design functional nanomaterials as novel probes biodetection. In contrast with conventional such organic dyes, exhibit high photostability unique size-dependent optical properties. Because their extinction coefficients strong distance dependent properties, these have emerged over past decade promising platform for rapid, highly sensitive colorimetric assays that allow visual detection low concentrations metal ions, small molecules, biomacromolecules. These discoveries deepened our knowledge biological phenomena facilitated development many new diagnostic therapeutic tools. Despite advances continued research efforts, current nanoparticle-based systems still suffer from several drawbacks, limited sensitivity selectivity. This Account describes recent based on protein enzyme-assisted nanoparticle amplification. benefits include significantly improved First, we discuss general enzyme-modified assays. We show quantitative properties different enzymes is paramount effective then examine nucleic acid types enzymes, including endonucleases, ligases, polymerases. For each assays, identify underlying principles contribute to enhanced capability illustrate them selected examples. Furthermore, demonstrate combination specific can probe enzyme dynamics function specificity, offering substantial advantages both specificity methods. screening nuclease, methyltransferase, protease, kinase activities be colorimetrically performed straightforward manner. Finally, examples ions molecules constitute important toward monitoring catalytic functions gene expression. Although assay methods hold promise myriad applications biomedicine bioimaging, application described techniques vivo faces formidable challenges. addition, researchers do not fully understand interactions molecules. will require substrate at particle interface higher spatial resolution specificity.