The sensors are screen printed and are able to detect molecular concentrations of fentanyl in one minute. The researchers suggest that the sensors could be manufactured for only a few cents and are disposable.
Current methods of classifying unknown drugs like fentanyl can be costly and have to be done in a laboratory. However, the UCSD-developed sensors could allow first responders, law enforcement officer and postal workers to use them quickly to easily detect fentanyl in the field or workplace to avoid dangerous exposure.
The on-the-spot detection strips are disposable and are similar to sensors that are used to monitor blood glucose, according to the researchers. They work through electrochemical detection to identify chemicals based on the voltage at which compounds are oxidized or reduced. When the compounds oxidize and reduce, there is a spike in electric current.
Using screen printing, electrodes were printed onto thin polymer sheets made from the same material that plastic bottles and food packaging are made from. The electrodes were then treated with an ionic liquid to stabilize them and allow fentanyl to gather on the surface.
The researchers suggest that screen printing can help reduce the cost of manufacturing the technology. Each sensor can cost just a few cents while handheld spectrometers that are typically used for drug detection can cost up to tens of thousands of dollars. The sensors are also able to be printed on fabric, allowing police officers to wear the sensors on a sleeve.
To test the technology, laboratory samples of fentanyl were applied to the sensor strips and inserted into a handheld electrochemical analyzer. The analyzer sends the information to a computer or tablet where the researchers can process the results on a computer to determine the concentration of fentanyl.
The research team plans to work on the sensors to produce direct readouts on the screen. They also hope to make sensors that could analyze more complex drug samples.
The research was published in the journal Analytical Chemistry and was supported by the Defense Threat Reduction Agency Joint Science and Technology Office for Chemical and Biological Defense and the Center for Wearable Sensors at UC San Diego.