%0 Journal Article
%T Carbon Fiber Ultramicrodic Electrode Electrodeposited with Over-Oxidized Polypyrrole for Amperometric Detection of Vesicular Exocytosis from Pheochromocytoma Cell
%A Li Wang
%A Huiren Xu
%A Yilin Song
%A Jinping Luo
%A Shengwei Xu
%A Song Zhang
%A Juntao Liu
%A Xinxia Cai
%J Sensors
%P 868-879
%D 2015
%I MDPI AG
%R 10.3390/s150100868
%X Vesicular exocytosis is ubiquitous, but it is difficult to detect within the cells¡¯ communication mechanism. For this purpose, a 2 ¦Ìm 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 ¦ÌA¡¤¦ÌM £¿1¡¤¦Ìm £¿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 (I max) and the released charge (Q) of the amperometric spikes from the DA release by a stimulated PC12 cell is 45.1 ¡À 12.5 pA and 0.18 ¡À 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.
%K amperometry
%K ultramicrodic carbon fiber electrode
%K over-oxidized polypyrrolenanoparicle
%K vesicular exocytosis
%U http://www.mdpi.com/1424-8220/15/1/868