Manring Noel, Ahmed Muzammil M N, Smeltz Jessica L, Pathirathna Pavithra
Department of Biomedical & Chemical Engineering & Sciences, Florida Institute of Technology, 150 W. University Blvd, Melbourne, FL, 32901, USA.
Anal Bioanal Chem. 2023 Jul;415(18):4289-4296. doi: 10.1007/s00216-022-04488-4. Epub 2023 Jan 3.
The etiology of neurodegenerative diseases is poorly understood; however, studies have shown that heavy metals, such as copper, play a critical role in neurotoxicity, thus, adversely affecting the development of these diseases. Because of the limitations associated with classical metal detection tools to obtain accurate speciation information of ultra-low concentrations of heavy metals in the brain, analysis is primarily performed in blood, urine, or postmortem tissues, limiting the translatability of acquired knowledge to living systems. Inadequate and less accurate data obtained with such techniques provide little or no information for developing efficient therapeutics that aid in slowing down the deterioration of brain cells. In this study, we developed a biocompatible, ultra-fast, low-cost, and robust surface-modified electrode with carbon fibers by electrodepositing dopamine via fast-scan cyclic voltammetry (FSCV) to detect Cu in modified tris buffer. We studied the surface morphology of our newly introduced sensors using high-resolution images by atomic force microscopy under different deposition conditions. The limit of detection (LOD) of our surface-modified sensor was 0.01 µM (0.64 ppb), and the sensitivity was 11.28 nA/µM. The LOD and sensitivity are fifty and two times greater, respectively, compared to those of a bare electrode. The sensor's response is not affected by the presence of dopamine in the matrix. It also exhibited excellent stability to multiple subsequent injections and repeated measurements of Cu over a month, thus showing its strength to be developed into an accurate, fast, robust electrochemical tool to monitor ultra-low concentrations of heavy metals in the brain in real time.
神经退行性疾病的病因目前仍知之甚少；然而，研究表明，重金属，如铜，在神经毒性中起着关键作用，从而对这些疾病的发展产生不利影响。由于传统金属检测工具在获取大脑中超低浓度重金属准确形态信息方面存在局限性，分析主要在血液、尿液或死后组织中进行，这限制了所获知识向活体系统的转化。用这些技术获得的数据不足且不够准确，几乎无法为开发有助于减缓脑细胞退化的有效疗法提供信息。在本研究中，我们通过快速扫描循环伏安法（FSCV）电沉积多巴胺，开发了一种具有生物相容性、超快速、低成本且坚固耐用的碳纤维表面修饰电极，用于检测修饰的三羟甲基氨基甲烷缓冲液中的铜。我们在不同沉积条件下，使用原子力显微镜的高分辨率图像研究了新引入传感器的表面形态。我们表面修饰传感器的检测限（LOD）为0.01 µM（0.64 ppb），灵敏度为11.28 nA/µM。与裸电极相比，检测限和灵敏度分别高出五十倍和两倍。传感器的响应不受基质中多巴胺存在的影响。它还对一个多月内多次后续注射和重复测量铜表现出优异的稳定性，从而显示出其有望发展成为一种准确、快速、坚固的电化学工具，用于实时监测大脑中超低浓度的重金属。
