Yüzüncü Yil University, Faculty of Science and Letter, Department of Analytical Chemistry, Campus Zeve, 65080 Van, Turkey.
Talanta. 2010 Jan 15;80(3):1347-55. doi: 10.1016/j.talanta.2009.09.035.
7,12-Dimethylbenz[a]anthracene (DMBA), is a widely studied polycyclic aromatic hydrocarbon that has long been recognized as a very potent carcinogen. Initially, the electrochemical oxidation of DMBA at the glassy carbon and pencil graphite electrodes in non-aqueous media (dimethylsulphoxide with lithium perchlorate) was studied by cyclic voltammetry. DMBA was irreversibly oxidized in two steps at high positive potentials, resulting in the ill-resolved formation of a couple with a reduction and re-oxidation wave at much lower potentials. Special attention was given to the use of adsorptive stripping voltammetry together with a medium exchange procedure on disposable pencil graphite electrode in aqueous solutions over the pH range of 3.0-9.0. The response was characterized with respect to pH of the supporting electrolyte, pre-concentration time and accumulation potential. Using square-wave stripping mode, the compound yielded a well-defined voltammetric response in acetate buffer, pH 4.8 at +1.15V (vs. Ag/AgCl) (a pre-concentration step being carried out at a fixed potential of +0.60V for 360s). The process could be used to determine DMBA concentrations in the range 2-10nM, with an extremely low detection limit of 0.194nM (49.7ngL(-1)). The applicability to assay of spiked human urine samples was also illustrated. Finally, the interaction of DMBA with fish sperm double-stranded DNA based on decreasing of the oxidation signal of adenine base was studied electrochemically by using differential pulse voltammetry with a pencil graphite electrode at the surface and also in solution. The favorable signal-to-noise characteristics of biosensor resulted in low detection limit (ca. 46nM) following a 300-s interaction. These results displayed that the electrochemical DNA-based biosensor could be used for the sensitive, rapid, simple and cost effective detection of DMBA-DNA interaction.
7,12-二甲基苯并[a]蒽（DMBA）是一种广泛研究的多环芳烃，长期以来被认为是一种非常有效的致癌物质。最初，通过循环伏安法研究了 DMBA 在非水介质（二甲基亚砜与高氯酸锂）中的玻璃碳和铅笔石墨电极上的电化学氧化。DMBA 在高正电势下不可逆地氧化为两步，导致在低得多的电势下形成一对还原和再氧化波。特别注意使用吸附溶出伏安法以及在 pH 值为 3.0-9.0 的水溶液中使用一次性铅笔石墨电极进行介质交换程序。响应特征与支持电解质的 pH 值、预浓缩时间和积累电位有关。使用方波溶出模式，在 pH 值为 4.8 的醋酸盐缓冲液中，该化合物在 +1.15V（相对于 Ag/AgCl）处产生了明确的伏安响应（在固定电位 +0.60V 下进行预浓缩 360s）。该过程可用于测定 2-10nM 范围内的 DMBA 浓度，检测限极低，为 0.194nM（49.7ngL(-1)）。还说明了该方法在测定加标人尿样中的适用性。最后，通过使用表面铅笔石墨电极的差分脉冲伏安法研究了 DMBA 与鱼精子双链 DNA 的相互作用，基于腺嘌呤碱基氧化信号的降低。生物传感器具有良好的信噪比特征，在 300s 的相互作用后，检测限低至约 46nM。这些结果表明，基于电化学的 DNA 生物传感器可用于敏感、快速、简单且经济有效的检测 DMBA-DNA 相互作用。
