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Patternable Rough Textured Gold Microwire for Neurochemical Sensing
Eva Mutunga
1
and Pawan Tyagi
2
1
Bredesen Center, University of Tennessee, 418 Greve Hall, 821 Volunteer Blvd, Knoxville, TN
37996, U.S.A.
2
Mechanical Engineering Department, University of the District of Columbia, 4200 Connecticut
Ave. N.W., Washington DC, U.S.A.
ABSTRACT
Understanding spatial and temporal neuronal activities is crucial for finding the cure for
brain related ailments and advancement of our knowledge about the brain itself. This paper
discusses our recent finding of the patternable rough textured gold microwire for neurochemical
sensing. We have successfully fabricated the ~5 μm wide and ~ 60 nm thick gold microwires
based electrochemical sensor. We produced these microwires along the edge of lithographically
patterned nickel thin film. A nickel thin film edge was shadowed by the photoresist overhang
during electrochemical growth only to allow gold deposition along the edges. Our
electrochemical growth conditions yielded very rough textured sensor. Rough textured
biosensors are highly desirable for increasing surface/volume ratio for efficient electrochemical
sensing. These rough-textured microwires were transformed into the functional neurochemical
sensor to detect dopamine. Our voltammetry and chronoamperometry studies on rough textured
microwires based sensor confirmed the successful detection of dopamine.
INTRODUCTION
Dopamine has been extensively studied as a result of its multifaceted importance within
neurobiological systems. Aside from being a precursor of adrenaline and noradrenaline,
dopamine also has an essential role in the neurological reward centers and pathways [1-3]. Some
of its notable functions are movement, memory, pleasurable reward, behavior, cognition,
attention, sleep, and mood. Dopaminergic neurons in the reward centers and pathways release the
particular neurotransmitter into the synaptic cleft, which causes a measurable, sub-second change
in concentration [4].
Dopamine quantity in the human body is limited. Having adequate levels of dopamine is,
therefore, essential to the overall health. Dopamine imbalances and defects in the dopaminergic
pathways are associated with neurological disorders and mental illnesses such as Parkinson’s
disease, psychosis, ADHD, and drug addiction [5,6].
Novel electrodes bring about a tremendous improvement in the electrochemical recording of
neurochemicals by enabling measurements with high spatial resolution and reduced disturbance
to the surrounding cells [7, 8]. In addition to revealing electrochemical processes that occur in
the nanoscale, microelectrodes offer a means to measure neurotransmitter concentrations around
synapses [2]. Nanostructures such as nanowires and carbon nanotubes have been used for
neurochemical recording, but these studies have been carried out using nanowire or carbon
nanotube clusters where the overall recording dimensions of the probes are several square
MRS Advances © 2016 Materials Research Society
DOI: 10.1557/adv.2016.31