Silicon-based microelectrode chips are useful tools for temporal recording of neurotransmitter releasing from
neural cells. Both invasive and non-invasive methods are targeted by different group researchers to perform
electrical stimulating on neural cells. A microfabricated microelectrodes integrated biochip will be presented in this
paper, which describes the dopaminergic cells growing on the chip directly. The dopamine exocytosis can be
detected non-invasively from drug incubated dopaminergic cells growing on the chip.
The abovementioned silicon-based electrochemical sensor chip has been designed with an electrode array located
on the bottom of reaction chamber and each electrode is individually electrical controlled. MN9D, a mouse
mesencephalic dopaminergic cell line, has been grown on the surface of the biochip chamber directly. Dopamine
exocytosis from the chip-grown MN9D cells was detected using amperometry technology. The amperometric
detection limit of dopamine of the biochip microelectrodes was found from 0.06μM to 0.21μM (S/N=3) statistically
for the electrode diameters from 10 μm to 90 μm, the level of dopamine exocytosis from MN9D cells was
undetectable whithout drug incubation. In contrast, after MN9D cells were incubated with L-dopa, a dopamine
precursor, K+ induced dopamine extocytosis was temporally detected.
The microelectrodes integrated biochip provides a non-invasive, temporal detection of dopamine exocytosis from
dopaminergic cells, and holds the potential for applications in studying the mechanisms of dopamine exocytosis,
and drug screening. It also provides a tool for pharmaceutical research and drug screening on dopaminergic cells,
extendably to be used for other cell culture and drug effects study.