Kwon, M. J. and Lee, J. and Wark, Alastair and Lee, Hye Jin (2012) Nanoparticle-enhanced surface plasmon resonance detection of proteins at attomolar concentrations : comparing different nanoparticle shapes and sizes. Analytical Chemistry, 84 (3). pp. 1702-1707. ISSN 0003-2700Full text not available in this repository. (Request a copy from the Strathclyde author)
The application of biofunctionalized nanoparticles possessing various shapes and sizes for the enhanced surface plasmon resonance (SPR) detection of a protein biomarker at attomolar concentrations is described. Three different gold nanoparticle shapes (cubic cages, nanorods and quasi-spherical) with each possessing at least one dimension in the 40-50 nm range were systematically compared. Each nanoparticle (NP) was covalently functionalized with an antibody (anti-thrombin) and used as part of a sandwich assay in conjunction with a Au SPR chip modified with a DNA-aptamer probe specific to thrombin. The concentration of each NP-antibody conjugate solution was first optimized prior to establishing that the quasi-spherical nanoparticles resulted in the greatest enhancement in sensitivity with the detection of thrombin at concentrations as low as 1 aM. When nanorod and nanocage antibody conjugates were instead used, the minimum target concentrations detected were 10 aM (rods) and 1 fM (cages). This is a significant improvement (>103) on previous NP-enhanced SPR studies utilizing smaller (~15 nm) gold NP conjugates and is attributed to the functionalization of both the NP and chip surfaces resulting in low nonspecific adsorption as well as a combination of density increases and plasmonic coupling inducing large shifts in the local refractive index at the chip surface upon nanoparticle adsorption.
|Keywords:||plasmon resonance detection , proteins, nanoparticle shapes , attomolar concentrations, Chemistry|
|Subjects:||Science > Chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
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|Depositing user:||Pure Administrator|
|Date Deposited:||25 Jan 2012 11:05|
|Last modified:||12 Jun 2013 14:33|
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