Researchers have fabricated a sensitive paper-based sensor that can detect minute traces of ketamine, a well-known anaesthetic drug used to produce sedative effects1.

Besides detecting the drug in biological fluids, this sensor will be potentially useful for finding ketamine in drinks, in which the drug is sometimes used to sedate and sexually abuse a victim.

Existing sensors for detecting ketamine are expensive and time consuming to make. To develop a simple sensor, biochemists from the Amity University, Noida and MD University, Haryana deposited a nanocomposite of zeolite nanocrystals and graphene oxide nanoflakes on a wax-modified filter paper.

They tested its efficiency in detecting ketamine in phosphate buffer solutions and in urine, alcoholic and non-alcoholic drinks. When exposed to ketamine-containing solutions, the sensor showed an increase in current response due to its large surface area and efficient electron transfer.

The sensor was able to selectively detect ketamine even in the presence of interfering agents such as flavouring and various active chemicals. It showed a good current response after 30 repeated experiments and retained its sensitivity even after being stored for two months.

“Since this sensor is paper-based, it is easy to use and cheaper than metal-based sensors,” says lead scientist, Jagriti Narang.