On-chip coulometric investigation of interactions between dopamine and nitric oxide
From LabAutopedia
Stephen T. Halpin
Michigan State University
Dana Spence
Michigan State University
Abstract:
Devices that enable a more realistic view of in vivo process using controlled in vitro platforms are becoming more popular based on literature citations. Specifically, the ability to monitor cell to cell communication through molecular signaling is an objective that our group has been working on for a few years. Key to the creation of such devices is the ability to integrate multiple modes of detection. Here, a device will be used to examine a possible link between the vascular system and nervous system by demonstrating an interaction between dopamine and endothelial cell-derived nitric oxide. Expanding upon previous work in developing carbon ink microelectrodes integrated into microfluidic devices, the work presented here will incorporate techniques developed by the microelectronics industry in developing printed circuit boards to demonstrate improvements in performance in carbon ink electrodes. This will require reference and auxiliary electrodes that are prepared using techniques used to prepare printed circuit boards. This simplifies the process of making electrical connections to the device, thereby moving closer to the goal of a plug-and-play device. Additionally, new data processing techniques are implemented that give the carbon ink electrode a longer useful life in addition to signal enhancement; specifically, by obtaining chronoamperometric data, which is then integrated using in-house developed software to yield coulometric data is used to extend electrode life, thus making the system more amenable to long-term automation and user-friendly data processing. Importantly, this system will improve detection limits of carbon ink electrodes for dopamine, facilitating their use in investigations of dopaminergic neurons. Furthermore, the presented device, which integrates 6 cell-interface channels with the microelectrode system, facilitates modular construction of each the electrode and cell layers. Because of this, it may be possible to prepare and culture the endothelial cells separate from the electrode; reducing risks of biofouling at the electrodes. To demonstrate feasibility, data will be presented using nitric oxide and dopamine as model analytes. Moreover, our group will provide evidence that a decrease in endothelium-derived nitric oxide production may actually leave dopamine levels unchecked, facilitating the addictive powers of cocaine, a suspected inhibitor of nitric oxide synthase in vivo.
