Electrochemical Biosensors

November 11, 2014 15:47 PSP Book - 9in x 6in 01-Serge-Cosnier-c01

Electrochemical Detection of Exocytosis 21

membrane and the vesicular matrix, as evidenced in PC12 cells [54,

55]. In fact, when observed by electron microscopy some vesicles

show an electron-lucent halo between the vesicle membrane and

the dense-core matrix [56], which was suggested to be the signature

of a medium in which the diffusion coefficient of neurotransmitters

is higher than in the compacted matrix. From such a perspective,

the foot frequency and kinetics should not be linked to dynamics

of the fusion pore but rather to the presence of halo-equipped

vesicles. Alternatively, the