CO/NO dual sensor enables in-vivo brain measurements
The IBS team has monitored the gas levels in real time during a seizure event and confirmed that CO and NO are closely involved in the activation of neuronal cells.
Inside our brains nerve cells signal each other using neurotransmitters including carbon monoxide (CO) and nitric oxide (NO) gases. Besides sharing a number of biological and chemical characteristics, CO and NO work together in regulating many physiological processes including vasodilatation, and immune reaction. Accurate and quantitative measurements of their physiological levels have been seen to result in meaningful findings and the focus of many previous studies but their similarities have prevented such effort from cracking the entangled bond between CO and NO.
The dual sensor is an amperometric microdevice, which is an electrical detection tool that is able to discern one specific molecule in a pool of many substances and count its concentration. What makes the solution so special is that the IBS device packs two separate sensors – one for CO, the other for NO exclusively – which can record in real time into a 300-µm probe, wich about twice the diameter of a human hair.
The probe is a construction of a 76-µm and a 50-µm platinum wires encased in thin, pulled glass capillary. The sensing tips of the probe are made of one gold and one platinum layers electroplated onto platinum substrates electrochemically etched to create recessed pores, resulting in a greater surface area (thus a higher sensitivity) for CO/NO detection. The fluorinated xerogel covering the tip prevents other biological interferents from obstructing the probe and allows the CO/NO gases to pass through selectively.
With miniaturized size and tapered needle-like shape, the dual sensor allowed the IBS team to record CO/NO within tissue during an acute seizure. Immediately after probe insertion, the IBS team was able to monitor almost dynamic changes in CO/NO levels.
Seizures have three distinct phases: initiation, propagation and termination. The dual sensor probe was able to record clearly defined changes in CO/NO levels which changed in accordance to the seizure’s phase changes.
“Subsequent further study needs to be performed for the clarification of a correlation between each seizure type and the associated pattern of CO/NO changes,” said Dr. Minah Suh of the research group. “Further studies will help to give more insights into the function and response of these neurotransmitters, laying the foundation for therapeutic applications for neuronal diseases.”
Reference
Yejin Ha, Jeongeun Sim, Youngmi Lee, and Minah Suh; Insertable Fast-Response Amperometric NO/CO Dual Microsensor: Study of Neurovascular Coupling During Acutely Induced Seizures of Rat Brain Cortex; Analytical Chemistry, DOI: 10.1021/acs.analchem.5b04288
Related articles and links:
News articles:
Implantantable sensors monitor brain injury before melting away
Wireless sensor measures blast-induced brain trauma shocks
Blue LED shows artificial skin sends pressure sensation to brain
If you enjoyed this article, you will like the following ones: don't miss them by subscribing to :
