Polydopamine-Functionalization of Graphene Oxide to Enable Dual Signal Amplification for Sensitive Surface Plasmon Resonance Imaging Detection of Biomarker

详细信息    查看全文

• 作者：Weihua Hu ; Guangli He ; Huanhuan Zhang ; Xiaoshuai Wu ; Jialin Li ; Zhiliang Zhao ; Yan Qiao ; Zhisong Lu ; Yang Liu ; Chang Ming Li
• 刊名：Analytical Chemistry
• 出版年：2014
• 出版时间：May 6, 2014
• 年：2014
• 卷：86
• 期：9
• 页码：4488-4493
• 全文大小：313K
• 年卷期：v.86,no.9(May 6, 2014)
• ISSN：1520-6882

文摘

Surface plasmon resonance imaging (SPRi) is one of the powerful tools for immunoassays with advantages of label-free, real-time, and high-throughput; however, it often suffers from limited sensitivity. Herein we report a dual signal amplification strategy utilizing polydopamine (PDA) functionalization of reduced graphene oxide (PDA-rGO) nanosheets for sensitive SPRi immunoassay in serum. The PDA-rGO nanosheet is synthesized by oxidative polymerization of dopamine in a gentle alkaline solution in the presence of graphene oxide (GO) sheets and then is antibody-conjugated via a spontaneous reaction between the protein and the PDA component. In the dual amplification mode, the first signal comes from capture of the antibody-conjugated PDA-rGO to form sandwiched immunocomplexes on the SPRi chip, followed by a PDA-induced spontaneous gold reductive deposition on PDA-rGO to further enhance the SPRi signal. The detection limit as low as 500 pg mL^鈥? is achieved on a nonfouling SPRi chip with high specificity and a wide dynamic range for a model biomarker, carcinoembryonic antigen (CEA) in 10% human serum.