Many people start their mornings with a steaming cup of coffee. Now, researchers have discovered an additional reason to adore coffee.
The American Chemical Society (ACS) recently published a paper describing the first use of used coffee grounds in electrochemistry and neuroscience. According to the researchers from ACS, coffee grounds can be used as environmentally friendly electrode coatings for sensitive neurochemistry measurements, which could help scientists better understand brain activity and detect minute levels of neurotransmitters. They will present their findings at the American Chemical Society’s spring meeting.
How Did The Researchers Recycle Their Coffee Waste?
Additionally, used coffee grounds were used to create porous carbon supercapacitors for energy storage. As with a battery, a supercapacitor is a device that stores and releases energy. Scientists have taken recycled coffee waste in a more biological direction as part of the new research, according to an ACS statement. They demonstrated in vitro that electrodes coated with carbon derived from coffee waste are capable of detecting trace levels of biomolecules (outside the living body). According to Ashley Ross, the study’s principal investigator, this is the first instance of residual coffee grounds being repurposed for biosensing applications. Biosensing is a technique for detecting target molecules that is based on the principles of a living system, such as an immune system.
According to Ross, she read papers on the use of spent grounds to create porous carbon for energy storage and considered the possibility of using the conductive material in neurochemistry detection work.
Neuroscientists employ conventional carbon fibre microelectrodes. Carbon fibre is made up of fine, solid carbon strands that are bundled together. Carbon fibre manufacturing is a lengthy and expensive process that involves several steps and harsh chemicals.
Ross’ goal, according to the statement, is to fabricate electrodes using carbon derived from coffee grounds. This is because it would be a low-cost and environmentally friendly solution. As a first step towards achieving the goal, the team coated conventional electrodes with ground coffee.
Coating Electrodes With Ground Coffee
One of the researchers dried used coffee grounds and heated them to approximately 1,300 degrees Fahrenheit in a tube furnace. The coffee grounds were then soaked in a potassium hydroxide solution to activate the carbon and create holes in the structure.
To eliminate undesirable byproducts, the team heated the mixture in the presence of nitrogen gas. An inky slurry flecked with porous carbon was left behind. After diluting the sludge with water, the researchers dipped the carbon fibre electrodes in it to coat them with a layer of porous carbon nearly a hundred times thinner than the diameter of a human hair.
Coating Electrodes With Coffee Facilitates Neurotransmitter Detection
The researchers compared the performance of coated and uncoated electrodes in sensing minute amounts of dopamine, a neurotransmitter, using fast-scan cyclic voltammetry, an electrochemical technique for measuring changing dopamine concentrations. It is sufficiently fast to detect subsecond neurotransmitter release, as occurs in the brain.
The researchers used the fast-scan cyclic voltammetry technique to alternately oxidise and reduce dopamine.