组蛋白促进[Ru(bpy)_2(dppz)]~(2+)和MWCNTs在ITO电极上的阳极共沉积

应用计时库仑法、循环伏安法、微分脉冲伏安法、荧光光谱和扫描电镜等方法研究了组蛋白(His)、Ru(bpy)2(dppz)]2+(bpy=2,2'-联吡啶,dppz=邻联二吡啶3,2-a:2',3'-c]吩嗪)和多壁碳纳米管(MWCNTs)在铟锡氧化物(ITO)电极上的电化学共沉积.结果表明,His能促进Ru(bpy)2(dppz)]2+和MWCNTs在ITO电极上的阳极共沉积(1.2 V vs.Ag/Ag Cl),所获得的复合膜呈现2对由表面电化学过程控制的氧化还原峰;通过研究His质量浓度和p H对复合膜中Ru(III)/Ru(II)氧化还原反应的影响,阐明了His作为媒介体调控Ru(bpy)2(dppz)]2+和MWCNTs在ITO电极上共沉积的机理.在优化的条件下,复合物中Ru(bpy)2(dppz)]2+发生氧化的电量在0.01~0.2mg/L和0.2~5.0 mg/L区间内与His质量浓度呈线性关系,其线性回归方程分别为ΔQ=3.24(±0.27)×10-6+2.95(±0.09)×10-4CHis(R=0.993)和ΔQ=5.92(±0.25)×10-5+6.26(±0.62)×10-6CHis(R=0.998).该研究建立的方法可应用于具有良好氧化还原性能的无机生物纳米复合材料的制备及蛋白质的固定与检测.

Anodic Co-Deposition of [Ru(bpy) 2(dppz)] 2+ and MWCNTs on an ITO Electrode Promoted by Histone

The electrochemical co-deposition of histone (His), Ru(bpy)2(dppz)]2+ (bpy = 2,2-bipyridine and dppz = dipyrido3,2-a:2,3-c]phenazine) and multi-walled carbon nanotubes (MWCNTs) on an indium-tin oxide (ITO) electrode has been investigated by means of chronocoulometry, cyclic voltammetry, differential pulse voltammetry, fluorescence spectroscopy and scanning electron microscopy. The presence of His is found to promote the co-deposition of Ru(bpy)2(dppz)]2+ and MWCNTs on the ITO electrode added at 1.2 V vs. Ag/AgCl. The prepared composite film shows two pairs of redox peaks controlled by surface electrochemical processes. Combined with the effects of His concentration and pH on the Ru(III)/Ru(II)-based redox reactions of the composite film, the electrochemical co-deposition mechanism of Ru(bpy)2(dppz)]2+ and MWCNTs on the ITO electrode mediated by His is further illustrated. Under the optimal conditions, the oxidative charges of Ru(bpy)2(dppz)]2+ in the composite film show a linear increase in the His concentration ranged between 0.01 ~ 0.2 mgL-1 and 0.2 ~ 5.0 mgL-1, the regression equations are described as Q/C = 3.24(0.27) 10-6 + 2.95 (0.09) 10-4 CHis/mgL-1 (R = 0.993) and Q/C = 5.92(0.25) 10-5 + 6.26 (0.62) 10-6 CHis/mgL-1 (R = 0.998). This study provides a new approach for the fabrication of redox-active inorganic bio-nanomaterials, as well as the immobilization and detection of proteins.