New sensor can rapidly detect RNA and DNA molecules

According to a new study from American University (AU), a tiny sensor used in brain chemistry research can rapidly identify the crucial molecules—DNA and RNA—that offer the genetic instructions for life.

According to the AU team, a sensor is a valuable tool for researchers focused on clinical studies to quantify the metabolism of DNA, and that the sensor could provide a rapid way for laboratory clinicians to differentiate between “healthy” and “sick” specimens and find out if a pathogen is fungal, viral, or bacterial, before performing additional analysis.

To investigate whether the sensors could identify DNA and RNA, Alexander Zestos, an assistant professor of chemistry, collaborated with John Bracht, an associate professor of biology, to verify a new technique for detecting DNA and RNA.

Both professors are part of the Center for Neuroscience and Behavior at American University, which brings together scientists from a wide range of fields to study the brain and its behavioral function.

The novel electrode measures RNA and DNA

Also called carbon-fiber microelectrodes, the sensors enable scientists like Zestos to perform accurate measurements of brain chemicals. Scientists can find out more about the brain’s intricate circuitry of neural pathways as well as neurotransmitters—chemicals in the brain that carry messages along a specified pathway.

Both Zestos and Bracht employed a standard carbon fiber microelectrode with fast-scan cyclic voltammetry, the same type of sensor used for detecting dopamine in the brain.

During studies, Zestos generally uses sensors to identify and quantify dopamine in the brain, because the neurotransmitter is involved in a broad range of activity in the nervous system, ranging from emotional responses to bodily movements.

The team altered the sensor with a dedicated electrode. But they were not certain that it would actually work and were quite amazed when the waveform, or electrode, identified the oxidative peaks of guanosine and adenosine, two of the DNA’s building blocks. The detection time is quick, taking place in less than a second. Experimental techniques were validated using animal as well as synthetic DNA and RNA.

A research tool and pre-diagnostic

In the near term, both Bracht and Zestos believe that the tool will be handy in clinical research. Scientists using the tool could obtain useful data about nucleic acids and quantify the relative ratios of guanosine, adenosine, and cytidine—another DNA nucleobase.

About the size of a single strand of human hair, the novel sensor is sufficiently small to be implanted in tissues, cells, or in live organisms. The sensor can identify RNA or DNA in all fluid samples, such as saliva, liquid droplets, urine, or blood.

The new sensor could even be utilized as a pre-diagnostic. The onset of fungal infection or disease can promote a rapid rise in nucleic acids, which can be measured by the sensor, and perhaps predict infections rapidly, added the researchers. For example, it can take up to a day or more for the test results from coronavirus,

Electrochemical sensors can be used for evaluating samples prior to sequence-based methods. We can envision several cases where clinically it's useful to quickly measure DNA or RNA in a sample before further sequencing. For example, it might be used when there are a lot of samples to quickly check before doing more extensive testing.”

John Bracht, Associate Professor of Biology, American University

One present restriction is that the sensor will need to identify more than just the DNA and RNA strands. For genetic testing or to identify a particular virus, the sensor should be able to detect a virus’s gene sequence.

The following step in the study will be to further alter the sensor to observe if it can identify a virus. The sensor could be used in a wide range of applications for which additional studies will be required, such as within forensic science and other fields where sensors play an important role.

We have also thought about whether we can measure DNA metabolism inside living brains and cells. We could possibly use one electrode to measure neurotransmitters like dopamine and also measure DNA and RNA and their building blocks in real-time in a brain.”

John Bracht, Associate Professor of Biology, American University