Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia (UKM), 43600, Bangi, Selangor Darul Ehsan, Malaysia.
Sci Rep. 2021 Apr 12;11(1):7883. doi: 10.1038/s41598-021-86939-z.
Ferrocene or ferrocenium has been widely studied in the field of organometallic complexes because of its stable thermodynamic, kinetic and redox properties. Novel hexaferrocenium tri[hexa(isothiocyanato)iron(III)]trihydroxonium (HexaFc) complex was the product from the reaction of ferrocene, maleic acid and ammonium thiocyanate and was confirmed by elemental analysis CHNS, FTIR and single crystal X-ray crystallography. In this study, HexaFc was used for the first time as an electroactive indicator for porcine DNA biosensor. The UV-Vis DNA titrations with this compound showed hypochromism and redshift at 250 nm with increasing DNA concentrations. The binding constant (K) for HexaFc complex towards CT-DNA (calf-thymus DNA) was 3.1 × 10 M, indicated intercalator behaviour of the complex. To test the usefulness of this complex for DNA biosensor application, a porcine DNA biosensor was constructed. The recognition probes were covalently immobilised onto silica nanospheres (SiNSs) via glutaraldehyde linker on a screen-printed electrode (SPE). After intercalation with the HexaFc complex, the response of the biosensor to the complementary porcine DNA was measured using differential pulse voltammetry. The DNA biosensor demonstrated a linear response range to the complementary porcine DNA from 1 × 10 to 1 × 10 µM (R = 0.9642) with a limit detection of 4.83 × 10 µM and the response was stable up to 23 days of storage at 4 °C with 86% of its initial response. The results indicated that HexaFc complex is a feasible indicator for the DNA hybridisation without the use of a chemical label for the detection of porcine DNA.
二茂铁或二茂铁阳离子由于其稳定的热力学、动力学和氧化还原性质，在有机金属配合物领域得到了广泛的研究。新型六茂铁三[六（异硫氰酸根合铁（III））]三羟基合（六茂铁）配合物是由二茂铁、马来酸和硫氰酸铵反应得到的产物，通过元素分析 CHNS、傅里叶变换红外光谱（FTIR）和单晶 X 射线晶体学得到了证实。在这项研究中，六茂铁首次被用作猪 DNA 生物传感器的电活性指示剂。该化合物与 DNA 的紫外可见 DNA 滴定实验显示，随着 DNA 浓度的增加，在 250nm 处出现了减色和红移现象。六茂铁配合物与 CT-DNA（小牛胸腺 DNA）的结合常数（K）为 3.1×10M，表明该配合物具有嵌入剂的行为。为了测试该配合物用于 DNA 生物传感器应用的有用性，构建了猪 DNA 生物传感器。识别探针通过戊二醛连接子共价固定在硅纳米球（SiNSs）上，然后固定在丝网印刷电极（SPE）上。与六茂铁配合物嵌入后，使用差分脉冲伏安法测量生物传感器对互补猪 DNA 的响应。该 DNA 生物传感器对互补猪 DNA 的线性响应范围为 1×10至 1×10µM（R=0.9642），检测限为 4.83×10µM，在 4°C 下储存 23 天，其初始响应的 86%保持稳定。结果表明，六茂铁配合物是一种可行的指示剂，可用于杂交而无需使用化学标记物来检测猪 DNA。
