Although they are the same alcohol, ethanol is used to make drinks, while methanol is a deadly toxic substance that takes lives. Recently, there have been multiple incidents in Southeast Asia where tourists have died after consuming counterfeit alcohol containing methanol. It is often impossible to distinguish it by appearance or smell, leading to frequent deceptions.
Australian scientists have developed a portable detector capable of sensing not only alcohol but also trace amounts of methanol in an individual's breath. This opens up a way to prevent harm from counterfeit alcohol without the need for expensive complex analytical equipment.
A research team led by Dusan Losic, a professor in the Department of Chemical Engineering at the University of Adelaide, stated on the 11th (local time) that they developed a wireless methanol detection sensor that is the size of a fingernail, capable of detecting methanol concentrations as low as 50 parts per million (ppm), equivalent to 1 ppm out of 1 million.
This level of concentration is low enough not to cause intoxication. The research team expressed hope that this device could help ensure drinking safety while traveling, as well as aid in the early diagnosis and treatment of methanol poisoning.
The sensor is made from graphene, a highly conductive material, and metal-organic frameworks (MOF). Graphene is a sheet-like substance where carbon atoms are bonded in a honeycomb structure, conducting electricity 1,000 times better than copper. MOF has a tremendously large surface area filled with numerous pathways and pores.
Even trace amounts of methanol can interact easily with the large surface area of MOF. Graphene detects methanol molecules by capturing the slight changes in electrical current during this interaction. The research team manufactured the sensor using 3D printing by spraying the two substances as ink onto a ceramic substrate. They also trained the sensor to differentiate between methanol, ethanol, and other toxic substances through artificial intelligence (AI) analysis.
Previously, gas chromatography-mass spectrometry (GC-MS) was mainly used to detect methanol. Although GC-MS is excellent for analyzing complex mixtures, it requires expensive equipment and expertise, making it impractical for regular consumers or travelers.
Professor Losic noted, "There is a desperate need for an affordable and portable detection device that can be easily used by medical personnel or the general public," adding, "This sensor demonstrates that it can detect very low concentrations of methanol in a very simple manner."
Counterfeit alcohol made from methanol poses a real threat to tourists visiting Southeast Asia. Last year, foreign tourists in popular tourist destinations in Thailand, Vietnam, and Laos died after consuming methanol-containing drinks. According to Médecins Sans Frontières (MSF), thousands suffer from methanol poisoning around the world each year, with 20% to 40% of these cases resulting in death.
Ethanol and methanol are both colorless liquids classified as alcohol, and they have similar odors. However, their uses are completely different. Ethanol is an expensive chemical used to produce alcoholic beverages such as beer, wine, and spirits. In contrast, methanol is an industrial chemical used as solid fuel, antifreeze, and wastewater treatment catalysts.
Methanol is highly toxic; even a small amount can be deadly. After ingestion, methanol begins to break down in the liver after a few hours, producing toxic byproducts such as formaldehyde and formic acid during this metabolic process. As these byproducts accumulate, they can attack the body's nerves and organs, leading to blindness, coma, or even death.
Professor Ian Musgrave, a toxicologist at the University of Adelaide, stated, "If there were a quick and simple device that could distinguish between regular alcohol, methanol, and other contaminants, it could greatly improve prevention and treatment of poisoning."
References
ACS Sensors (2025), DOI: https://doi.org/doi/10.1021/acssensors.4c03281