6-糠氨基嘌呤的电化学行为及与DNA的相互作用

应用循环伏安法、微分脉冲伏安法和紫外光谱法研究了6-糠氨基嘌呤(6-KT)在汞电极上的电化学行为及与小牛胸腺DNA的相互作用.结果发现,6-KT的循环伏安曲线显示两对表征为扩散控制和吸附控制的氧化还原波.扩散控制波的氧化峰电流随6-KT浓度在1.00×10-4～5.00×10-2mmol·L-1范围内呈现良好的线性关系.依据预吸附时间和溶液pH值对吸附控制波的还原峰电位和峰电流的影响,讨论了6-KT在汞电极上的吸附机理.另外,6-KT的扩散控制波的还原峰电流随DNA浓度的增加而减小,峰电位正移,紫外吸收峰出现明显的减色效应,认为6-KT乃通过部分插入作用与DNA结合,结合常数为2.60×103 L·mol-1.     

6-苄氨基嘌呤的电化学行为及与DNA的相互作用

应用循环伏安法、微分脉冲伏安法和紫外光谱法研究了6-苄氨基嘌呤(6-BA)在汞电极上的电化学行为,及与小牛胸腺DNA的相互作用.结果发现,6-BA的循环伏安曲线显示三对扩散或吸附控制的氧化还原波.扩散波的氧化峰电流随6-BA浓度在0.1～50.0 μmol·L-1范围内呈现良好的线性关系.依据预吸附时间和溶液pH值对吸附波的还原峰电位和峰电流的影响,讨论了6-BA在汞电极上的咐附机理.另外,6-BA的还原峰电流随DNA浓度的增加而减小,峰电位正移,紫外吸收峰出现明显的减色效应,认为6-BA通过部分插入作用与DNA结合,结合常数为2.3×103L·mol-1.     

6-取代嘌呤的电化学行为及与DNA的相互作用

应用循环伏安法和微分脉冲伏安法研究了6-糠氨基嘌呤(6-KT)和6-巯基嘌呤(6-MP)在汞电极上的电化学行为及与小牛胸腺DNA的相互作用.结果发现,6-KT和6-MP的循环伏安曲线均显示两对分别表征为扩散控制和吸附控制的氧化还原波.扩散控制波的氧化峰电流随6-取代嘌呤浓度在0.1~50.0μmol.L-1范围内呈现良好的线性关系.依据预吸附时间和溶液pH值对吸附控制波的还原峰电位和峰电流的影响,讨论了6-KT和6-MP在汞电极上的吸附机理.作者认为,6-KT乃通过部分插入作用与DNA结合,而6-MP与DNA间的相互作用为静电模式.     

2,2'-联吡啶In(Ⅲ)配合物与DNA作用的电化学研究

应用循环伏安法、微分脉冲伏安法和交流阻抗法研究了配合物In(bpy)Cl3.H2O与DNA在Tris-HCl缓冲溶液(pH=7.2)中的相互作用.结果表明:配合物中心In(Ⅲ)离子的循环伏安曲线上呈现一对准可逆的氧化还原波,DNA与配合物作用后,配位中心离子的氧化还原峰电流明显降低,扩散系数减小,电化学反应阻抗增大,式量电位负移,表明该配合物与DNA的作用方式为静电结合.     

2，2′-联吡啶In（Ⅲ）配合物与DNA作用的电化学研究

应用循环伏安法、微分脉冲伏安法和交流阻抗法研究了配合物In(bpy)Cl3·H2O与DNA在Tris-HCl缓冲溶液(pH=7.2)中的相互作用.结果表明配合物中心In(Ⅲ)离子的循环伏安曲线上呈现一对准可逆的氧化还原波,DNA与配合物作用后,配位中心离子的氧化还原峰电流明显降低,扩散系数减小,电化学反应阻抗增大,式量电位负移,表明该配合物与DNA的作用方式为静电结合.     

丹酚酸B与牛血清白蛋白相互作用的电化学研究

在0.01 mol.L-1磷酸盐缓冲溶液(pH 7.4)中,用循环伏安法和方波伏安法研究了丹酚酸B与牛血清白蛋白相互作用前后在DNA修饰玻碳电极上的电化学行为。实验表明,丹酚酸B在此修饰电极上于0.100 V处产生良好的氧化峰,加入牛血清白蛋白后,丹酚酸B的电子转移系数α和表观电子传递速率常数ks均发生了变化,氧化峰电位正移,峰电流减小。根据氧化电流的变化求得丹酚酸B和牛血清白蛋白相互作用的结合常数β=1.00×108L.mol-1,结合数m=1.71,表明丹酚酸B与牛血清白蛋白生成了结合比约为2∶1的非电活性复合物。该结果与荧光光谱法的研究结果一致。     

纳米金修饰碳糊电极上甲氨蝶呤的电化学测定及其与鲱鱼精DNA相互作用的研究

制备了纳米金修饰碳糊电极,使用循环伏安法(CV)研究了甲氨蝶呤(MTX)在该修饰电极上的电化学特性,并建立了纳米金修饰碳糊电极电化学测定MTX的新方法.利用线性扫描伏安法(LSV)和方波伏安法(SWV)研究了MTX与鲱鱼精DNA的相互作用.实验发现,在pH 3.6 HAc-NaAc缓冲溶液中,MTX在0.86 V处有一灵敏的氧化峰,氧化峰电流Ipa与MTX的浓度在0.5 ～10.0 μmol·L-1范围内呈良好的线性关系,方法检出限(S/N=3)为0.2μmol·L-1.对3.0 μmol·L-1的MTX进行11次平行测定,其RSD为4.7％.该修饰电极可用于MTX样品的测定,结果满意.当不同浓度鲱鱼精DNA加入MTX溶液后,氧化峰电位正移,氧化峰电流降低,表明MTX与鲱鱼精DNA之间发生了相互作用,形成了非电活性化合物.电化学研究表明,MTX与鲱鱼精DNA之间的结合比为2∶1,结合常数为4.6×105 L·mol-1.     

粉防己碱在玻碳电极上的电化学行为及其与DNA的相互作用

应用循环伏安法、差分脉冲伏安法、控制电位电解法等电化学方法和紫外光谱法研究了粉防己碱在玻碳电极上的电化学行为及其与DNA的相互作用,并对相关电化学动力学参数进行考察。结果表明,粉防己碱在玻碳电极上发生了受扩散控制的不可逆氧化反应,其在玻碳电极上的电子转移数为2、质子转移数为2、电荷转移系数为0.62。粉防己碱的峰电流随着DNA的加入而降低,且峰电位发生正移,表明粉防己碱与DNA通过嵌插方式相互作用生成复合物,同时计算了两者反应的结合数以及结合常数,结果显示粉防己碱和DNA以1∶1结合形成粉防己碱-DNA复合物,结合常数为4.27×103。     

粉防己碱在玻碳电极上的电化学行为及其与DNA的相互作用

应用循环伏安法、差分脉冲伏安法、控制电位电解法等电化学方法和紫外光谱法研究了粉防己碱在玻碳电极上的电化学行为及其与DNA的相互作用,并对相关电化学动力学参数进行考察。结果表明,粉防己碱在玻碳电极上发生了受扩散控制的不可逆氧化反应,其在玻碳电极上的电子转移数为2、质子转移数为2、电荷转移系数为0.62。粉防己碱的峰电流随着DNA的加入而降低,且峰电位发生正移,表明粉防己碱与DNA通过嵌插方式相互作用生成复合物,同时计算了两者反应的结合数以及结合常数,结果显示粉防己碱和DNA以1∶1结合形成粉防己碱-DNA复合物,结合常数为4.27×103。     

喷他脒和DNA相互作用的光谱及电化学研究

应用循环伏安法,差示脉冲伏安法,紫外光谱法研究了喷他脒和DNA的相互作用.在pH 8.5的0.1 mol/L Na2HPO4-NaH2PO4缓冲溶液中,喷他脒于电位-1.56 V处有一灵敏的还原波,向其溶液中加入DNA,喷他脒峰电位稍微负移,峰电流下降;DNA使喷他脒的紫外吸收光谱发生紫移且增色,DNA和喷他脒相互作用形成1:2非电活性缔合物,结合数为2,结合常数为3.55×10-6.     

Electrochemical study on oxidation of ofloxacin at nano-ZnS/poly (Styrene sulfonic acid sodium salt) modified electrode and its interaction with calf thymus DNA

A PSS/nano-ZnS thin film modified electrode has been fabricated on the surface of glassy carbon electrode (GCE). In pH 5.0 phosphate buffer solution (PBS), Ofloxacin (OFX) appeared as an anodic peak with the peak potential of 1.28 V at PSS/nano-ZnS film modified electrode. In comparison with a bare GCE or a nano-ZnS modified electrode, the PSS/nano-ZnS film modified electrode exhibited an enhanced effectiveness for the oxidation of OFX. Cyclic voltammetry (CV) coupled with fluorescence and UV-vis absorbance spectra techniques were used to study the interaction of OFX with Calf thymus DNA (ctDNA). The interaction of OFX and ctDNA could result in a considerable decrease in the peak currents and positively shift in the peak potential, as well as changes of fluorescence, UV-Vis adsorption spectra. All acquired data showed that the new adduct between OFX and ctDNA was formed. Published in Russian in Elektrokhimiya, 2009, Vol. 45, No. 3, pp. 289–295. The article is published in the original.     

电活化玻碳电极差分脉冲伏安法测定水杨酸的研

采用循环伏安法和差分脉冲伏安法对水杨酸在电活化玻碳电极上的电化学行为进行研究.在pH7.0的PBS溶液中,将玻碳电极用恒电位法在+1.7V电位阳极氧化400 s.在0.2 mol·L- NaOH溶液中,水杨酸在0.602 V处有一良好的氧化峰,其氧化峰电流与扫描速率在0.02～0.2 V·s-1范围内呈良好线性关系,表...     

用银-色氨酸复合膜修饰玻碳电极循环伏安法测定去甲肾上腺素

在含有1.0mmol.L-1硝酸银、5.58×10-2 mol.L-1色氨酸的溶液中,于-0.8～1.8V(vs.Ag/AgCl)电位下,在玻碳电极表面电沉积一层银-色氨酸复合膜,制得银-色氨酸复合膜修饰玻碳电极(Ag-TRY/GCE)。采用扫描电镜对电极表面的性能进行表征,循环伏安法对其电化学性能进行研究。试验发现:在pH 6.0磷酸盐缓冲溶液中,去甲肾上腺素(NE)在修饰电极出现一对明显的氧化还原峰,氧化峰电位为0.306V,还原峰电位为0.368V,提出了用循环伏安法测定NE的方法。在试验条件下,氧化峰电流与去甲肾上腺素浓度在3.4×10-7～8.3×10-6 mol.L-1和8.3×10-6～1.1×10-4 mol.L-1两段范围内呈线性关系,检出限(3S/N)为4.3×10-8 mol.L-1。修饰电极用于药物中去甲肾上腺素的测定,加标回收率在95.6%～99.4%之间。     

Synthesis of a New Cobalt (II) Complex and its Interaction with DNA

The interaction of metal complexes with DNA has been widely studied by differentmethods such as spectrophotometry, light scattering technique, fluorometry1-3. Manycomplexes such as Co(phen)2 ,Co(en)2 ,Fe(EDTA)2- etc.4,5 have been synthesized and 3+ 3+their effect on DNA has been studied in order to further explain the mechanism of genemutation, anti-cancer or cancer-induced reason and DNA targeted drugs. In this paper,a new cobalt complex was synth…     

Electrochemical and Spectroscopic Studies on the Interaction of Malachite Green with DNA and Its Application

The interaction of malachite green (MG) with double‐stranded DNA (dsDNA) in pH 7.0 Britton–Robinson (B–R) buffer solution was investigated by electrochemical and spectrophotometric methods. Within the potential scan range of ?1.0 to +1.5 V (vs. SCE), MG has two oxidative peaks at 0.547 V and 0.833 V and one reductive peak at 0.362 V on cyclic voltammogram at the scan rate of 0.20 V/s. After the addition of dsDNA into the MG solution, the oxidative peak current at 0.547 V decreases obviously. The electrochemical parameters, such as the charge transfer coefficient (α), the surface reaction rate constant (k_s) and the diffusion coefficient (D), were calculated and compared between in the absence and presence of dsDNA. The results show that these parameters of MG after adding dsDNA have greatly changed, which indicates that an electrochemical active complex was formed. The interaction mechanisms of MG with dsDNA are discussed in some details from the electrochemistry and UV‐vis spectrophotometry. The reduction of the peak current of MG after adding dsDNA was further used for the quantification of dsDNA by differential pulse voltammetry (DPV). The linear range for dsDNA is in the range of 10.0–100.0 μg/mL with the linear regression equation as Δi_p (μA)=0.065+0.0096 C (μg/mL) and the detection limit of 6.0 μg/mL (3σ). The influences of coexisting substances were investigated and artificial samples were determined with satisfactory results.     

Electrochemical Determination of Natural Drug Colchicine in Pharmaceuticals and Human Serum Sample and its Interaction with DNA

Colchicine (COLC) is a natural toxic product and secondary metabolite most commonly used to treat gout. In this study, its electrochemical behavior and determination was investigated by employing modification‐free boron‐doped diamond electrode (BDDE). Besides, its interaction with DNA was monitored using electrochemical methods. It was found that oxidation of this compound proceeds in two steps, where first sharp and well defined oxidation peak occurs at potential of around 1.19 V, and second one at around 1.37 V, in Britton‐Robinson buffer solution at pH 7.5. Wide dynamic range from 1 to 100 μM was obtained with a detection limit (3σ_intercept/slope) of a 0.26 μM, based on the evaluation of first oxidation peak using differential pulse voltammetry. The proposed method was also found to be suitable for monitoring interaction of this drug with DNA as important segment for medical use. Concerning the validation, the analytical procedure shows excellent selectivity and sensitivity toward COLC detection and after method development it was successfully used for its quantification in pharmaceutical preparation and human serum sample, with satisfactory recovery. Obviously, this approach can be promising replacement for time‐consuming and expensive separation methods.     

Voltammetry of the Erythromycin-Modified Glassy Carbon Electrode and Interaction With Dna

ABSTRACT

The chemically modified electrode (CME) which was constructed by covalently attaching Erythromycin (ERM) to a glassy carbon (GC) surface was investigated in Tris-HCl buffer (pH=6.0) by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In the potential range -0.5 to +0.4V, CME yields a pair of stable redox waves. It is the carbonyl group of the ERM molecule immobilized on the GC surface that behaves as a two-electron redox process involving one proton. The interaction of CME with DNA was also studied by DPV. The CME shows the same interaction with DNA as that in the solution. And the interactive model between ERM and DNA was proved by fluorescence in aqueous solutions.     

博莱霉素与DNA在镍离子注入修饰电极上的相互作用 及其应用

博莱霉素(BLM)在0.1mol/LHOAc-NaOAc缓冲溶液(pH4.62)中,在Ni/GCE离子注入修饰电极上有一灵敏的还原峰,峰电位为-1.16V(vs.SCE),峰电流与BLM浓度有关。用线性扫描和循环伏安法研究体系的行为表明,体系为具有加速作用的不可逆过程,是注入的Ni加速BLM的还原。引入DNA后,BLM的峰电位为-1.15V(vs.SCE),与未加入DNA前几乎完全一致;只使峰电流降低,形成一种非电活性的结合物,求得该结合物的结合比为BLM：DNA=3：1,结合常数为β=3.16×10^16,用线性扫描和循环伏安法,并辅以紫外可见光谱法等手段研究表明,电极过程仍为不可逆过程,与未加入DNA时一样。加入DNA后,BLM的峰电流降低,可用于DNA的测定,回收率在96.8～103.9%之间.     

邻苯三酚红修饰碳糊电极吸附伏安法测定痕量铜

报道了采用邻苯三酚红修饰碳糊电极测定痕量铜的方法。通过在邻苯二甲酸氢钾 -氢氧化钠 (p H4.5)介质中富集 ,Cu2 +和邻苯三酚红形成络合物富集于电极表面 ,然后转换到 0 .0 50 mol· L-1的 H3PO4 中 ,经阴极还原后再进行阳极溶出伏安法测定。Cu2 +浓度在 1 .6× 1 0 -9～ 2 .8× 1 0 -7mol·L-1范围内与二次导数峰电流呈线性关系 ,检出限达 8× 1 0 -10 mol·L-1。同时 ,对电极反应机理进行了探讨。应用于合金样的测定 ,取得满意的结果。