New way of testing for cocaine discovered

March 14, 2019 by Grant Hill, University of Dundee

Researchers from the University of Dundee have developed a new chemical sensor for cocaine that may lead to potential new point of seizure tests for police officers, customs officers, prison officers and medical professionals who routinely test for controlled substances.

The new, specific colour-spot test has been developed by Dr. Oluwasesan Adegoke and colleagues at the University's Leverhulme Research Centre for Forensic Science (LRCFS).

Forensic laboratories are often called upon to identify tablets, liquids and unknown powders that may contain a controlled drug but, in many cases, the first responding officers seek to determine whether or not a suspected substance contains an using an 'off the shelf' presumptive test kit.

These commercially available chemical spot test kits have been intensively used by for decades but their underpinning chemistry remains speculative or unknown in some cases. As a result, they are increasingly being challenged in terms of specificity, particularly as new drugs emerge onto the illicit market.

Mixtures of several drugs within powders can give a false positive reading, which could lead to either controlled substances being undetected or a person being incorrectly charged with possession of a particular drug.

In response to this, Dr. Adegoke has utilised a buffer solution that the suspected cocaine is dropped in before being mixed with other sensor components. Within two minutes, a clear colour change specific to cocaine was seen. The analysis of several substances and drugs showed no interference to the sensor, demonstrating its selectivity to cocaine.

"This will obviously be of interest to law enforcement and other agencies," said Dr. Adegoke. "When starting this project we were trying to overcome certain challenges in the detection of controlled substances, one of which is the false positive readings for cocaine arising from the presence of several different compounds.

"This test is very specific to cocaine. We tried it with other substances and it wasn't found to work. It takes advantage of cocaine's unique chemical structure and the chemicals in the sensor have a strong affinity to the in comparison with the others we tested.

"We hope to do a follow up study in the future which may involve detecting cocaine in urine which will have relevance to because if someone is experiencing then they want to know what they have taken."

The research has been published in the latest edition of the journal Sensors and Actuators B: Chemical.

The method developed by LRCFS staff uses a novel hybrid fluorescent nanozyme peroxidase-mimic catalytic sensor to detect the presence of . Nanozymes are nanomaterials-based enzyme mimics that are produced synthetically to mimic the properties of natural enzymes, proteins that speed up and facilitate reactions in living things.

Dr. Adegoke added, "Hybrid nanozymes hold great promise for application in forensic science. This work is an excellent proof-of-concept colorimetric sensor technique that with a tweak of chemistry can be exploited for the detection of other targets of forensic interest."

The Leverhulme Research Centre for Forensic Science is a 10-year £10 million funded research centre which aims to disrupt the current ecosystem.

Explore further: Researchers patent quick tests for cocaine

More information: Oluwasesan Adegoke et al. Multi-shaped cationic gold nanoparticle-l-cysteine-ZnSeS quantum dots hybrid nanozyme as an intrinsic peroxidase mimic for the rapid colorimetric detection of cocaine, Sensors and Actuators B: Chemical (2019). DOI: 10.1016/j.snb.2019.02.074

Related Stories

Understanding addiction in the adolescent mind

November 1, 2017

Several studies have provided strong evidence that adolescents—people in their teens to early twenties—have a higher vulnerability than adults to addictive substances like cocaine. To understand the origin of the age ...

New test detects drug use from a single fingerprint

May 15, 2015

Research published today in the journal Analyst has demonstrated a new, noninvasive test that can detect cocaine use through a simple fingerprint. For the first time, this new fingerprint method can determine whether cocaine ...

Recommended for you

A decade on, smartphone-like software finally heads to space

March 20, 2019

Once a traditional satellite is launched into space, its physical hardware and computer software stay mostly immutable for the rest of its existence as it orbits the Earth, even as the technology it serves on the ground continues ...

Tiny 'water bears' can teach us about survival

March 20, 2019

Earth's ultimate survivors can weather extreme heat, cold, radiation and even the vacuum of space. Now the U.S. military hopes these tiny critters called tardigrades can teach us about true toughness.

Researchers find hidden proteins in bacteria

March 20, 2019

Scientists at the University of Illinois at Chicago have developed a way to identify the beginning of every gene—known as a translation start site or a start codon—in bacterial cell DNA with a single experiment and, through ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Mar 14, 2019
I've been waiting for a laser spectrography and solid-state electronics to meld with a car-mounted version driving around detecting it in the air. When it detects the signature above a threshold, it alerts you.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.