Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, Tamilnadu, India.
Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi 630003, Tamilnadu, India.
J Colloid Interface Sci. 2018 Nov 15;530:202-211. doi: 10.1016/j.jcis.2018.06.046. Epub 2018 Jun 23.
Deoxyribonucleic acid (DNA), a primary unit of heredity in all types of organisms, consists of purine and pyrimidine bases in such a way that the amount of guanine (GU) is equal to cytosine (CY) and the amount of adenine (AD) is equal to thymine (TY). Any abnormalities in the concentration of these four bases will have significant influence on disease diagnosis, crime detection and biocomputing applications of DNA. Hence, identification and quantification of either individual or group of these DNA bases are important for diagnosis of certain diagnosis and genetic disorders. In the present work, we report the fabrication of an efficient electrochemical sensor for simultaneous determination of purine (GU, AD) and pyrimidine (CY, TY) bases using Cu doped CeO nanoparticles modified glassy carbon electrode (Cu-CeO/GCE). The direct electrocatalytic activities of DNA bases have been studied using voltammetric techniques in phosphate buffer solution (PBS, pH 7.0) without any enzyme or mediator. 3 wt% Cu doped CeO modified GCE showed two well defined anodic peaks each towards the oxidation of purine and pyrimidine bases with significant peak to peak potential separation of 312 mV (AD-GU) and 200 mV (TY-CY) which were large enough for the selective and simultaneous determination of these bases in their mixture. Under optimum conditions, calibration plots for the simultaneous detection of the purine and pyrimidine bases were linear in the concentration range of 0.1-500 μM for AD, 1-650 μM for GU, 1-300 μM for TY and 1-250 for CY with the lowest detection limit values of 0.021, 0.031, 0.024, and 0.038 μM respectively. Additionally, the developed sensor exhibited good repeatability, reproducibility, sufficient stability and good anti-interference ability and was successfully applied for simultaneous detection of AD, GU, TY and CY in denatured DNA sample with satisfactory results.
脱氧核糖核酸（DNA）是所有类型生物遗传的主要单位，由嘌呤和嘧啶碱基组成，其中鸟嘌呤（GU）的含量等于胞嘧啶（CY），腺嘌呤（AD）的含量等于胸腺嘧啶（TY）。这四种碱基浓度的任何异常都会对疾病诊断、犯罪检测和 DNA 的生物计算应用产生重大影响。因此，鉴定和定量这些 DNA 碱基中的任何一种或一组对于某些疾病的诊断和遗传疾病的诊断都很重要。在本工作中，我们报告了一种使用掺铜的 CeO 纳米粒子修饰玻碳电极（Cu-CeO/GCE）同时测定嘌呤（GU、AD）和嘧啶（CY、TY）碱基的高效电化学传感器的制备。在磷酸盐缓冲溶液（PBS，pH 7.0）中，无需使用任何酶或介体，通过伏安技术研究了 DNA 碱基的直接电催化活性。3wt%Cu 掺杂的 CeO 修饰的 GCE 对嘌呤和嘧啶碱基的氧化各显示出两个定义明确的阳极峰，其峰到峰电位分离为 312mV（AD-GU）和 200mV（TY-CY），足以用于这些碱基在混合物中的选择性和同时测定。在最佳条件下，同时检测嘌呤和嘧啶碱基的校准曲线在 AD 的浓度范围为 0.1-500μM、GU 的浓度范围为 1-650μM、TY 的浓度范围为 1-300μM 和 CY 的浓度范围为 1-250μM，最低检测限分别为 0.021、0.031、0.024 和 0.038μM。此外，该传感器表现出良好的重复性、重现性、足够的稳定性和良好的抗干扰能力，并成功地用于变性 DNA 样品中 AD、GU、TY 和 CY 的同时检测，结果令人满意。
