Mixed Stimuli-Responsive Magnetic and Gold Nanoparticle System for Rapid Purification, Enrichment, and Detection of Biomarkers

详细信息    查看全文

• 作者：Michael A. Nash ; Paul Yager ; Allan S. Hoffman ; Patrick S. Stayton
• 刊名：Bioconjugate Chemistry
• 出版年：2010
• 出版时间：December 15, 2010
• 年：2010
• 卷：21
• 期：12
• 页码：2197-2204
• 全文大小：390K
• 年卷期：v.21,no.12(December 15, 2010)
• ISSN：1520-4812

文摘

A new diagnostic system for the enrichment and detection of protein biomarkers from human plasma is presented. Gold nanoparticles (AuNPs) were surface-modified with a diblock copolymer synthesized using reversible addition−fragmentation chain transfer (RAFT) polymerization. The diblock copolymer contained a thermally responsive poly(N-isopropylacrylamide) (pNIPAAm) block, a cationic amine-containing block, and a semi-telechelic PEG<sub>2sub>-biotin end group. When a mixed suspension of 23 nm pNIPAAm-modified AuNPs was heated with pNIPAAm-coated 10 nm iron oxide magnetic nanoparticles (mNPs) in human plasma, the thermally responsive pNIPAAm directed the formation of mixed AuNP/mNP aggregates that could be separated efficiently with a magnet. Model studies showed that this mixed nanoparticle system could efficiently purify and strongly enrich the model biomarker protein streptavidin in spiked human plasma. A 10 ng/mL streptavidin sample was mixed with the biotinylated pNIPAAm-modified AuNPs and magnetically separated in the mixed nanoparticle system with pNIPAAm mNPs. The aggregates were concentrated into a 50-fold smaller fluid volume at room temperature where the gold nanoparticle reagent redissolved with the streptavidin target still bound. The concentrated gold-labeled streptavidin could be subsequently analyzed directly using lateral flow immunochromatography. This rapid capture and enrichment module thus utilizes the mixed stimuli-responsive nanoparticle system to achieve concentration of a gold-labeled biomarker that can be directly analyzed using lateral flow or other rapid diagnostic strategies.