in vivo Testing of a Microsensor

Our focus has been on neurotransmitter sensing, and our first important contribution in this area was the creation of a Pt microwire-based probe for glutamate (the most important excitory neurotransmitter in the mammalian brain) that exhibited high selectivity while maintaining a rapid response time of <1 sec. This breakthrough feat was achieved by discovering the favorable permselective barrier properties of an electrodeposited polypyrrole film after over-oxidation. We later transferred successfully this technology to ~120 µm microprobes micromachined from Si wafers. These microprobes are designed with multiple microelectrode sites that led to our creation of devices for combined sensing of both glutamate and dopamine and to our incorporation of an on-probe reference microelectrode. For the first time, these probes have enabled our neuroscience collaborators to monitor glutamate signaling events in near-real-time in the basolateral amygdala of freely moving rats engaged in reward-seeking behavior. This pathbreaking collaborative research is continuing with NIH funding and our dual sensing probes. We also are working with engineering and neuroscience groups to incorporate on-probe microoptics and to integrate our chemical sensing technology with that for electrophysiological recordings.

 

Students

 

• Lili Feng
• Liwen (Brenda) Huang
• Bo Wang
• Allison Yorita

 

 

Publications

 

N. Hamdi, J. Wang, H.G. Monbouquette, Polymer films as permselective coatings for H2O2-sensing electrodes, J. Electroanal. Chem., 581, 258-264 (2005)

 

N. Hamdi, J. Wang, E. Walker, N.T. Maidment, H.G. Monbouquette, An electroenzymatic L-glutamate microbiosensor selective against dopamine, J. Electroanal. Chem., 591, 33-40 (2006)

 

E. Walker, J. Wang, N. Hamdi, H.G. Monbouquette, N.T. Maidment, Selective detection of extracellular glutamate in brain tissue using microelectrode arrays coated with over-oxidized polypyrrole, Analyst, 132, 1107-1111 (2007)

 

Wassum, Kate M., Tolosa, Vanessa M., Wang, Jianjun, Walker, Eric, Monbouquette, Harold G., Maidment, Nigel T., Silicon Wafer-Based Platinum Microelectrode Array Biosensor for Near-Real-Time Measurement of Glutamate in vivo, Sensors, 8, 5023-5036 (2008)

 

Wassum, Kate M., Tolosa, Vanessa M., Tseng, Tina C., Balleine, Bernard W., Monbouquette, Harold G., Maidment, Nigel T., Transient Extracellular Glutamate Events in the Basolateral Amygdala Track Reward-Seeking Actions, J. Neurosci., 32(8), 2734-2746 (2012)

 

Tseng, Tina T.-C., Monbouquette, Harold G., Implantable microprobe with arrayed microsensors for combined amperometric monitoring of the neurotransmitters, glutamate and dopamine, J. Electroanal. Chem., 682, 141-146 (2012)

 

Tolosa, Vanessa M., Wassum, Kate M., Maidment, Nigel T., Monbouquette, Harold G., Electrochemically deposited iridium oxide reference electrode integrated with an electroenzymatic glutamate sensor on a multi-electrode array microprobe, Biosens. Bioelectron., 42, 256-260 (2013)