How coffee could wake up the detection of brain waves

If you feel your brain starts percolating when you drink coffee, it does give you a metabolic boost, but the grounds left over in the filter have been mostly ignored until now.

Used coffee grounds only seem useless. They are hiding carbon that has been turned into an eco-friendly coating for electrodes which detect activity in the brain, like the levels of neurotransmitters being zapped to other cells by neurons. When these coatings were made with the porous carbon extract from coffee grounds and tested out for dopamine detection, not only were more dopamine molecules adsorbed (adhered to the surface but not absorbed) by the material, but they were also caught in the micro-pores. Did that just wake you up?

For a team of researchers from the University of Cincinnati, who presented their results at the recent meeting for the American Chemical Society, this was the best excuse ever to buy more coffee. The electrode coatings are so effective that they can pick up amounts of neurotransmitters that are barely there. Neuroscientists usually detect these chemicals, which brain cells transmit as directions for what they want other cells to do, with microelectrodes made of extremely thin carbon fibers. These are produced through a long, expensive process that involves harmful substances. Coffee cuts cost and time and solves pollution problems.

Dopamine, which the research team was looking for, is one of the seven main neurotransmitters in the brain. Grabbing that morning latte might mean a jolt of dopamine for hardcore coffee lovers. This is the famous — or infamous, depending on how you see it — chemical that switches on feelings of pleasure known as a “dopamine rush.” Unfortunately, this effect that can keep you coming back for more has also linked dopamine to addiction. The brain still needs this hormone despite its negative associations. Having a dopamine deficiency can mean everything from memory loss to gastrointestinal issues to severe depression.

Adjusting levels of dopamine or any neurotransmitter means knowing how much is being produced by the brain. This is where microelectrodes, which can find that out along with other neurobiological functions, come in. Making these sensors out of the carbon in coffee grounds required heating the grounds to extreme temperatures, then adding a potassium hydroxide solution to activate the carbon and create holes for a porous structure. To get rid of unwanted byproducts, more heat was applied under nitrogen gas, leaving behind a thick ooze.

To get to the carbon, that viscous mixture needed to be diluted with water. Carbon fiber electrodes were then dipped into it for an invisibly thin coating of porous carbon. Both coated and uncoated electrodes were put through a technique known as fast-scan cyclic voltammetry, which can detect neurotransmitters at speeds under a second, as rapidly as they are released in the brain. The electrode was zapped with superfast voltage that kept changing in intensity, so it would oxidize and reduce dopamine from one pulse to the next.

Turns out the gunk left in your coffee filter could lead to some mind-blowing advancements in neurology. Those electrodes with the coating of porous carbon ended up being more sensitive to dopamine. Dopamine generated the oxidative current at the end of the electrode, and the oxidative current levels the coated fibers could reach were found to be triple what the uncoated fibers were capable of. The porous coating gave each electrode a larger surface area, with the added plus of adsorbing more dopamine molecules and having pores to trap them with.

More research is brewing. The team is looking to make the carbon fibers themselves from the porous carbon that comes out of coffee grounds. This would result in a completely porous electrode that has added surface area and more openings for dopamine molecules to run into momentarily, which could also make detection faster. They just need to keep drinking coffee.