Electrochemiluminescent Sensing for Caspase-3 Activity Based on Ru(bpy)32+-Doped Silica Nanoprobe

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• 作者：Yong-Ping Dong ; Gang Chen ; Ying Zhou ; Jun-Jie Zhu
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：February 2, 2016
• 年：2016
• 卷：88
• 期：3
• 页码：1922-1929
• 全文大小：561K
• ISSN：1520-6882

文摘

Caspase-3 is one of the most frequently activated cysteine proteases during the apoptosis process and has been identified as a well-established cellular marker of apoptosis. In this study, a novel approach for the sensitive determination of caspase-3 activity was proposed using electrochemiluminescence (ECL) of Ru(bpy)₃p>2+p>-doped silica (Ru@SiO₂) with tripropylamine (TPA) as coreactant. A nanocomposite containing gold nanoparticles (AuNPs), poly(dimethyldiallyl ammonium chloride) (PDDA), and multiwalled carbon nanotubes (CNTs) was fabricated as an ECL platform. The biotinylated DEVD-peptide (biotin-Gly-Asp-Gly-Asp-Glu-Val-Asp-Gly-Cys) was immobilized on the nanocomposite surface via the strong bonding interaction between AuNPs and the thiol group. Then the streptavidin-modified Ru(bpy)₃p>2+p>-doped silica (Ru@SiO₂-SA) was immobilized on the ECL platform via the specific interaction between biotin and streptavidin to generate ECL signal. Caspase-3 can specifically recognize and cleave the N-terminus of DEVD, leading to the loss of the biotin label and the decrease of ECL intensity to determine the activity of caspase-3. The results revealed a new ECL avenue for the sensitive and specific monitor of caspase-3, and the platform could be utilized to evaluate anticancer drugs.