Nano Archive

Ag/SiO2 core-shell nanoparticle-based surface-enhanced Raman probes for immunoassay of cancer marker using silica-coated magnetic nanoparticles as separation tools

Gong, Ji-Lai and Liang, Yi and Huang, Yong and Chen, Ji-Wei and Jiang, Jian-Hui and Shen, Guo-Li and Yu, Ru-Qin (2007) Ag/SiO2 core-shell nanoparticle-based surface-enhanced Raman probes for immunoassay of cancer marker using silica-coated magnetic nanoparticles as separation tools. BIOSENSORS & BIOELECTRONICS, 22 (7). pp. 1501-1507.

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Official URL: http://dx.doi.org/10.1016/j.bios.2006.07.004

Abstract

A simple, sensitive and highly specific immunoassay has been developed based on surface-enhanced Raman scattering for human alpha-fetoprotem (AFP), a tumor marker for the diagnosis of hepatocellular carcinoma. This strategy combines the Ag/SiO2 core-shell nanoparticles embedded with rhodamine B isothiocyanate dye molecules as Raman tags and the amino group modified silica-coated magnetic nanoparticle as immobilization matrix and separation too]. In the proposed system, a sandwich-type immunoassay was performed between polyclonal antibody functionalized Ag/SiO2 nanoparticle-based Raman tags and monoclonal antibody modified silica-coated magnetic nanoparticles. The presence of the analyte and the reaction between the antigen and antibody can be monitored by the Raman spectra of the Ag/SiO2 tags. Compared to the previous surface-enhanced Raman immunoassays, the main advantage of this strategy lies in two aspects. One is the high stability of Raman tags derived from the silica shell-coated silver core-shell nanostructure. The other is the use of silica-coated magnetic nanoparticles as immobilization matrix and separation tool, thus avoiding complicated pretreatment and washing steps. We have studied in detail the experimental parameters such as the effects of the antibody concentration modified on the Raman tags and on the magnetic particles, and the immunoreaction time. Using this strategy, concentration of human AFP up to 0.12 mu g/ml was detected with a detection limit of 11.5 pg/ml. (c) 2006 Elsevier B.V. All rights reserved.

Item Type:Article
Uncontrolled Keywords:surface-enhanced Raman scattering; Raman tags; magnetic nanoparticles; immunoassay
Subjects:Physical Science > Nano objects
Physical Science > Nanomagnetics
Biomedical Science > Nanomedicine
Analytical Science > Beam methods
ID Code:2619
Deposited By:Anuj Seth
Deposited On:09 Jan 2009 15:24
Last Modified:20 Jan 2009 11:31

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