Department of Biochemistry, Panjab University, Chandigarh, 160014, India.
Department of Biochemistry, Panjab University, Chandigarh, 160014, India; Department of Chemistry and Centre for Advanced Studies in Chemistry, Panjab University, Chandigarh, 160014, India.
Biosens Bioelectron. 2025 Jan 1;267:116783. doi: 10.1016/j.bios.2024.116783. Epub 2024 Sep 18.
Vitamin B12 is an essential micronutrient required for the proper functioning of the human body. Vitamin B12 deficiency is primarily causative of various neurolological disorders alongwith recurrence of oral ulcers and burning sensations which are early signs of condition such as pernicious anemia. Other complications associated with Vitamin B12 deficiency include risk of heart failure due to anemia, risk of developing autoimmune disorders and gastric cancer. Therefore, to obstruct these communal health issues, early detection of Vit B12 is highly needed. However, screening of vitamin B12 insufficiency is hindered by the low sensitivity of the conventional vitamin B12 test. Holotranscobalamin (holoTC) is an early indicator of the negative vitamin B12 balance as it is the first protein to decline in the serum. We report a novel impedimetric immunosensor based on flower-like poly (3,4-ethylenedioxythiophene) (PEDOT) nanostructural film impregnated with silver molybdate nanoparticles (AgMoO₄ NPs) deposited on fluorine-doped tin oxide electrode. The prepared electrodes were characterized by Field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and electrochemical studies. The activated anti-holoTC antibody was immobilized and optimized to capture the target in a response time of 15 min. The electrochemical performance of the sensor was carried out by using the electrochemical impedance spectroscopy technique (EIS) and a good linear relationship between ΔR and holoTC was obtained in the range from 0.1 pg mL to 100 ng mL with a detection limit of 0.093 pg mL. The proposed sensor was successfully applied in human serum samples for holoTC detection. The experimental results showed that the immunosensor is highly selective towards holoTC and presented an acceptable stability of 20 days with reproducibility RSD ≤4%. To the best of our knowledge, this is the first developed electrochemical immunosensor for holoTC detection.
维生素 B12 是人体正常功能所必需的微量营养素。维生素 B12 缺乏主要导致各种神经紊乱，同时还会反复发作口腔溃疡和烧灼感，这是恶性贫血等疾病的早期症状。与维生素 B12 缺乏相关的其他并发症包括由于贫血导致心力衰竭的风险、自身免疫性疾病和胃癌的风险。因此，为了阻止这些公共卫生问题，非常需要早期检测 Vit B12。然而，由于常规维生素 B12 测试的灵敏度低，维生素 B12 不足的筛查受到阻碍。全钴胺素（holoTC）是维生素 B12 负平衡的早期指标，因为它是血清中第一个下降的蛋白质。我们报告了一种基于花状聚（3,4-亚乙基二氧噻吩）（PEDOT）纳米结构薄膜的新型阻抗免疫传感器，该薄膜中浸渍有银钼酸盐纳米粒子（AgMoO₄ NPs）沉积在掺氟氧化锡电极上。通过场发射扫描电子显微镜（FE-SEM）和能量色散 X 射线光谱（EDS）、X 射线衍射（XRD）和电化学研究对制备的电极进行了表征。将激活的抗 holoTC 抗体固定化并进行了优化，以在 15 分钟的响应时间内捕获靶标。通过使用电化学阻抗谱技术（EIS）进行传感器的电化学性能测试，并在 0.1 pg mL 至 100 ng mL 的范围内获得了 ΔR 与 holoTC 之间的良好线性关系，检测限为 0.093 pg mL。该传感器成功应用于人血清样品中 holoTC 的检测。实验结果表明，该免疫传感器对 holoTC 具有高度选择性，并且在 20 天的时间内具有可接受的稳定性，重现性 RSD ≤4%。据我们所知，这是第一个用于检测 holoTC 的电化学免疫传感器。
