Department of Chemistry and Biomolecular Science, Potsdam, NY 13699-5810, USA.
Anal Chim Acta. 2011 Jun 10;695(1-2):89-95. doi: 10.1016/j.aca.2011.03.057. Epub 2011 Apr 7.
We report the development of a chitosan modified carbon fiber microelectrode for in vivo detection of serotonin. We find that chitosan has the ability to reject physiological levels of ascorbic acid interferences and facilitate selective and sensitive detection of in vivo levels of serotonin, a common catecholamine neurotransmitter. Presence of chitosan on the microelectrode surface was investigated using scanning electron microscopy (SEM) and cyclic voltammetry (CV). The electrode was characterized using differential pulse voltammetry (DPV). A detection limit of 1.6 nM serotonin with a sensitivity of 5.12 nA/μM, a linear range from 2 to 100 nM and a reproducibility of 6.5% for n=6 electrodes were obtained. Chitosan modified microelectrodes selectively measure serotonin in presence of physiological levels of ascorbic acid. In vivo measurements were performed to measure concentration of serotonin in the live embryonic zebrafish intestine. The sensor quantifies in vivo intestinal levels of serotonin while successfully rejecting ascorbic acid interferences. We demonstrate that chitosan can be used as an effective coating to reject ascorbic acid interferences at carbon fiber microelectrodes, as an alternative to Nafion, and that chitosan modified microelectrodes are reliable tools for in vivo monitoring of changes in neurotransmitter levels.
我们报告了一种壳聚糖修饰碳纤维微电极的开发，用于活体检测血清素。我们发现壳聚糖具有排斥生理水平抗坏血酸干扰的能力，并有助于选择性和敏感地检测活体中常见的儿茶酚胺神经递质血清素的水平。使用扫描电子显微镜（SEM）和循环伏安法（CV）研究了微电极表面壳聚糖的存在。使用差分脉冲伏安法（DPV）对电极进行了表征。获得了 1.6 nM 血清素的检测限，灵敏度为 5.12 nA/μM，线性范围为 2 至 100 nM，6 个电极的重现性为 6.5%。壳聚糖修饰的微电极在存在生理水平抗坏血酸的情况下选择性地测量血清素。进行了活体测量，以测量活体斑马鱼肠道中血清素的浓度。该传感器可定量活体肠道中的血清素，同时成功地排除了抗坏血酸的干扰。我们证明壳聚糖可用作碳纤维微电极的有效涂层，以排斥抗坏血酸干扰，替代 Nafion，并且壳聚糖修饰的微电极是用于活体监测神经递质水平变化的可靠工具。
