Donmez Soner, Arslan Fatma, Arslan Halit
Department of Chemistry, Faculty of Science and Art, Nevsehir Haci Bektas Veli University, 50300, Nevsehir, Turkey,
Appl Biochem Biotechnol. 2015 Jul;176(5):1431-44. doi: 10.1007/s12010-015-1655-6. Epub 2015 May 7.
An electrochemical nucleic acid biosensor based on label-free DNA detection method was prepared for the first time by using electropolymerized poly(L-glutamic acid)-modified pencil graphite electrode (PGA/PGE) for detection of hepatitis C virus genotype 1a (HCV1a). Inosine-substituted 20-mer probes related to the HCV1a were immobilized onto PGA/PGE surface by covalent linking with the formation of amide bonds. Square wave voltammetry (SWV) was used to monitor the oxidation signal of guanine in the hybridization events, which gave an oxidation peak at +1.05 V. An increase in the oxidation signal of guanine was showed by hybridization of the probe with the complementary DNA. Noncomplementary oligonucleotides were also used to investigate the selectivity of the biosensor. The proposed nucleic acid biosensor was linear in the range of 50 nM to 1.0 μM, exhibiting a limit of detection of 40.6 nM. Finally, single-stranded synthetic PCR product analogues of HCV1a were performed in optimal condition. This PGA-modified nucleic acid sensor is cost-effective and disposable, and besides, it has superior electrocatalytic effect on the oxidation of guanine.
首次制备了一种基于无标记DNA检测方法的电化学核酸生物传感器，该传感器使用电聚合聚（L-谷氨酸）修饰的铅笔石墨电极（PGA/PGE）来检测丙型肝炎病毒1a型（HCV1a）。与HCV1a相关的肌苷取代的20聚体探针通过形成酰胺键的共价连接固定在PGA/PGE表面。采用方波伏安法（SWV）监测杂交事件中鸟嘌呤的氧化信号，其氧化峰出现在+1.05 V处。探针与互补DNA杂交显示鸟嘌呤氧化信号增加。还使用非互补寡核苷酸来研究生物传感器的选择性。所提出的核酸生物传感器在50 nM至1.0 μM范围内呈线性，检测限为40.6 nM。最后，在最佳条件下对HCV1a的单链合成PCR产物类似物进行了检测。这种PGA修饰的核酸传感器具有成本效益且可一次性使用，此外，它对鸟嘌呤的氧化具有优异的电催化作用。
