title: Carbon fiber ultramicrodic electrode electrodeposited with over-oxidized polypyrrole for amperometric detection of vesicular exocytosis from pheochromocytoma cell.
abstract: Vesicular exocytosis is ubiquitous, but it is difficult to detect within the cells' communication mechanism. For this purpose, a 2 µm ultramicrodic carbon fiber electrode was fabricated in this work based on electrodeposition with over-oxidized polypyrrole nanoparticle (PPyox-CFE), which was applied successfully for real-time monitoring of quantal exocytosis from individual pheochromocytoma (PC12) cells. PPyox-CFE was evaluated by dopamine (DA) solutions through cyclic voltammetry and amperometry electrochemical methods, and results revealed that PPyox-CFE improved the detection limit of DA. In particular, the sensitivity of DA was improved to 24.55 µA·µM(-1)·µm(-2) using the PPyox-CFE. The ultramicrodic electrode combined with the patch-clamp system was used to detect vesicular exocytosis of DA from individual PC12 cells with 60 mM K+ stimulation. A total of 287 spikes released from 7 PC12 cells were statistically analyzed. The current amplitude (Imax) and the released charge (Q) of the amperometric spikes from the DA release by a stimulated PC12 cell is 45.1 ± 12.5 pA and 0.18 ± 0.04 pC, respectively. Furthermore, on average ~562,000 molecules were released in each vesicular exocytosis. PPyox-CFE, with its capability of detecting vesicular exocytosis, has potential application in neuron communication research.
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. wangli2011iecas@163.com.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. xuhuiren_2012@163.com.
authors.forename: Huiren
authors.initials: H
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. ylsong@mail.ie.ac.cn.
authors.forename: Yilin
authors.initials: Y
authors.lastname: Song
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. jpluo@mail.ie.ac.cn.
authors.forename: Jinping
authors.initials: J
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. swxu@mail.ie.ac.cn.
authors.forename: Shengwei
authors.initials: S
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. zhangsong0112@126.com.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. jpluo@mail.ie.ac.cn.
authors.forename: Juntao
authors.initials: J
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China. xxcai@mail.ie.ac.cn.
authors.forename: Xinxia
authors.initials: X
authors.lastname: Cai
mesh_terms: D000310:Adrenal Gland Neoplasms / Q000473:pathology; D000818:Animals; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D004298:Dopamine / Q000032:analysis; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D004595:Electroplating / Q000379:methods*; D005089:Exocytosis; D010084:Oxidation-Reduction; D010673:Pheochromocytoma / Q000473:pathology*; D011108:Polymers / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D051381:Rats; D059629:Signal-To-Noise Ratio; D013997:Time Factors; D022161:Transport Vesicles / Q000378:metabolism*
chemical_list: D000077482:Carbon Fiber; D011108:Polymers; D011758:Pyrroles; C067635:polypyrrole; D002244:Carbon; D004298:Dopamine