School of Chemistry & Environment, Beijing University of Aeronautics & Astronautics, Xueyuan Rd. #37, Haidian District, Beijing 100191, China.
Biosens Bioelectron. 2011 Jan 15;26(5):2781-5. doi: 10.1016/j.bios.2010.10.041. Epub 2010 Oct 31.
Herein, a rapid electrochemical biosensor for L-histidine based on highly specific, L-histidine-dependent DNAzymes is described. DNA with a single, sessile ribo-adenine, self-cleaves in the presence of L-histidine, allowing a ferrocene tag to transfer electrons to the electrode. The double-stranded DNA complex was chemi-absorbed to a gold electrode via a 3' terminal thiol. The signal of this proposed sensor is linear over the range, 1 nM to 10 μM, with R=0.98775. To improve signal intensity, gold nanoparticles were anchored to a gold electrode surface which had been previously modified with self-assembled monolayers of 1,6-hexanedithiol. With gold nanoparticle modification, a lower detection limit of 0.1 pM L-histidine and a good linear relationship over the range, 0.1 pM to 50 nM were obtained. The proposed biosensor presents high specificity for L-histidine, is not affected by the presence of other amino acids, and demonstrates excellent enantio-selectivity toward L-histidine. This proposed sensor protocol offers reasonable selectivity, rapid speed, and operational convenience for real sample assays.
本文描述了一种基于高度特异性、依赖 L-组氨酸的 DNA 酶的 L-组氨酸的快速电化学生物传感器。在 L-组氨酸存在下，具有单个固定核糖腺嘌呤的 DNA 会自我切割，从而使二茂铁标记物能够将电子转移到电极上。双链 DNA 复合物通过 3'末端硫醇化学吸附到金电极上。该传感器的信号在 1 nM 至 10 μM 的范围内呈线性，R=0.98775。为了提高信号强度，将金纳米粒子锚定到先前用 1,6-己二硫醇自组装单层修饰的金电极表面。通过金纳米粒子修饰，获得了较低的检测限为 0.1 pM L-组氨酸和 0.1 pM 至 50 nM 范围内的良好线性关系。该生物传感器对 L-组氨酸具有高选择性，不受其他氨基酸的影响，并且对 L-组氨酸表现出优异的对映体选择性。该传感器方案为实际样品分析提供了合理的选择性、快速的速度和操作方便性。
