PDF(Pubmed)
Abstract：
Fast-scan cyclic voltammetry (FSCV) is an electrochemical sensing technique that can be used for neurochemical sensing with high spatiotemporal resolution. Carbon fiber microelectrodes (CFMEs) are traditionally used as FSCV sensors. However, CFMEs are prone to electrochemical fouling caused by oxidative byproducts of repeated serotonin (5-HT) exposure, which makes them less suitable as chronic 5-HT sensors. Our team is developing a boron-doped diamond microelectrode (BDDME) that has previously been shown to be relatively resistant to fouling caused by protein adsorption (biofouling). We sought to determine if this BDDME exhibits resistance to electrochemical fouling, which we explored on electrodes fabricated with either femtosecond laser cutting or physical cleaving. We recorded the oxidation current response after 25 repeated injections of 5-HT in a flow-injection cell and compared the current drop from the first with the last injection. The 5-HT responses were compared with dopamine (DA), a neurochemical that is known to produce minimal fouling oxidative byproducts and has a stable repeated response. Physical cleaving of the BDDME yielded a reduction in fouling due to 5-HT compared with the CFME and the femtosecond laser cut BDDME. However, the femtosecond laser cut BDDME exhibited a large increase in sensitivity over the cleaved BDDME. An extended stability analysis was conducted for all device types following 5-HT fouling tests. This analysis demonstrated an improvement in the long-term stability of boron-doped diamond over CFMEs, as well as a diminishing sensitivity of the laser-cut BDDME over time. This work reports the electrochemical fouling performance of the BDDME when it is repeatedly exposed to DA or 5-HT, which informs the development of a chronic, diamond-based electrochemical sensor for long-term neurotransmitter measurements in vivo.
摘要：
快速扫描循环伏安法（FSCV）是一种电化学传感技术，可用于具有高时空分辨率的神经化学传感。碳纤维微电极(CFME)传统上用作FSCV传感器。然而,CFME容易因反复接触5-羟色胺（5-HT）的氧化副产物而导致电化学结垢，这使得它们不太适合作为慢性5-HT传感器。我们的团队正在开发一种硼掺杂的金刚石微电极（BDDME），该电极先前已被证明对蛋白质吸附（生物污染）引起的污染具有相对抵抗力。我们试图确定这种BDDME是否表现出对电化学污染的抵抗力，我们在飞秒激光切割或物理切割制造的电极上进行了探索。我们记录了在流动注射池中重复注射25次5-HT后的氧化电流响应，并比较了从第一次注射到最后一次注射的电流下降。将5-HT反应与多巴胺（DA）进行比较，一种神经化学物质，已知产生最少的污垢氧化副产物，并具有稳定的重复反应。与CFME和飞秒激光切割的BDDME相比，BDDME的物理切割减少了由于5-HT引起的结垢。然而,飞秒激光切割的BDDME比切割的BDDME的灵敏度大大提高。在5-HT污染测试之后,对所有装置类型进行扩展的稳定性分析。该分析表明，与CFME相比，硼掺杂金刚石的长期稳定性有所改善，以及随着时间的推移激光切割BDDME的灵敏度下降。这项工作报告了BDDME反复暴露于DA或5-HT时的电化学结垢性能，这说明了慢性疾病的发展，基于金刚石的电化学传感器，用于体内长期神经递质测量。
