Chiroplasmonic Assemblies of Gold Nanoparticles for Ultrasensitive Detection of 8-Hydroxy-2′-deoxyguanosine in Human Serum Sample

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• 作者：Yuanjian Liu ; Min Wei ; Linqun Zhang ; Yuanjian Zhang ; Wei Wei ; Lihong Yin ; Yuepu Pu ; Songqin Liu
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：June 21, 2016
• 年：2016
• 卷：88
• 期：12
• 页码：6509-6514
• 全文大小：364K
• 年卷期：0
• ISSN：1520-6882

文摘

Gold nanoparticles (AuNPs) have been extensively explored to be used in analytical methods such as electrochemical, colorimetric methods, and so on. However, only a few methods have been reported by using chirality of AuNPs although their chiral assembly has been studied extensively and circular dichroism (CD) spectroscopy is also a simple and sensitive analytical method. In this paper, sensitive CD spectroscopy method has been explored for detection of 8-hydroxy-2′-deoxyguanosine (8-OHdG), a well-known biomarker for oxidative DNA damage, based on DNA-induced chiroplasmonic assemblies of AuNPs. First, 8-OHdG aptamer hybridized with its complementary sequence that modified with AuNPs based on precision matched bases. DNA-modified AuNPs were assembled into AuNPs dimers by 8-OHdG aptamer, which displayed strong chiroptical activity. Subsequently, in the presence of 8-OHdG, the high specific recognition and affinity constants of aptamer and 8-OHdG destroyed the hybrid of aptamer and its complementary sequence; as a result, AuNPs dimers were destroyed and showed low CD signal. The CD intensity was in log–linear correlation with the concentration of 8-OHdG ranging from 0.05 to 2 nM, with a correlation coefficient of 0.9951 and a detection limit of 33 pM (S/N = 3). The method has been successfully applied in a complex matrix such as human serum samples. The recoveries were from 92.5% to 107% and the relative standard derivations were in the range of 4.89% ∼ 7.27%, indicating that the method had good accuracy and high precision. Therefore, these results indicated that the proposed CD method was simple and reliable, which held great potential for clinical examinations.