Sensitive DNA biosensor improved by Luteolin copper(II) as indicator based on silver nanoparticles and carbon nanotubes modified electrode

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• 作者：Shuyan Niu ; Bin Han ; Wei Cao ; Shusheng Zhang
• 关键词：Luteolin copper ; Carbon nanotube ; 4-Aminobenzoic acid ; Silver nanoparticles ; Electrochemical DNA biosensor
• 刊名：Analytica Chimica Acta
• 出版年：2009
• 出版时间：28 September 2009
• 年：2009
• 卷：651
• 期：1
• 页码：42-47
• 全文大小：781 K

文摘

A novel and sensitive electrochemical DNA biosensor has been developed for the detection of DNA hybridization. The biosensor was proposed by using copper(II) complex of Luteolin C₃₀H₁₈CuO₁₂ (CuL₂) as an electroactive indicator based on silver nanoparticles and multi-walled carbon nanotubes (Ag/MWCNTs) modified glassy carbon electrode (GCE). In this method, the 4-aminobenzoic acid (4-ABA) and Ag nanoparticles were covalently grafted on MWCNTs to form Ag/4-ABA/MWCNTs. The proposed method dramatically increased DNA attachment quantity and complementary ssDNA detection sensitivity for its large surface area and good charge-transport characteristics. DNA hybridization detection was performed using CuL₂ as an electroactive indicator. The CuL₂ was synthesized and characterized using elemental analysis (EA) and IR spectroscopy. Cyclic voltammetry (CV) and fluorescence spectroscopy were used to investigate the interaction between CuL₂ and ds-oligonucleotides (dsDNA). It was revealed that CuL₂ presented high electrochemical activity on GCE, and it could be intercalated into the double helices of dsDNA. The target ssDNA of the human hepatitis B virus (HBV) was quantified in a linear range from 3.23 × 10⁻¹² to 5.31 × 10⁻⁹ M (r = 0.9983). A detection limit of 6.46 × 10⁻¹³ M (3σ, n = 11) was achieved.