Our bodies’ molecules are constantly communicating with one another. Some of these molecules offer a biochemical fingerprint that may reveal how a wound is healing, whether or not cancer treatment is effective, or whether a virus has entered the body. We might be able to identify health issues more quickly and even track the progression of disease if we could detect these signals in real time with high sensitivity.
In order to listen in on our bodies’ internal conversations, Northwestern University researchers have now developed a new technology.
The body’s chemical signals are extremely weak, making it challenging to identify and analyze them. However, the researchers have created a new technique that amplifies signals by more than 1,000 times. The electronic component transistors have the ability to strengthen weak signals and produce amplified outputs. By eliminating complicated and large electronics, the new method makes signals easier to detect.
“We could put those sensors into wearable devices or implants that have a small footprint, less weight, and don’t require expensive electronics if we could accurately analyze biochemical signals in the body,”
Northwestern’s Jonathan Rivnay, the study’s senior author.
The new method moves modern medicine one step closer to real-time, on-site disease monitoring by enabling the amplification of weak biochemical signals.
Nature Communications, a journal, published the study on Saturday.
“If we could accurately measure biochemical signals in the body, we could incorporate those sensors into wearable technologies or implants that have a small footprint, are less burdensome, and don’t require expensive electronics,” said Jonathan Rivnay, a senior author from Northwestern University and co-author of the study. “However, obtaining high-quality signals has remained difficult. You must find methods to amplify those signals due to the body’s constrained power and space.”.
The McCormick School of Engineering at Northwestern University employs Rivnay as a professor of biomedical engineering. The paper’s primary author is Xudong Ji, a post-doctoral researcher in Rivnay’s lab.
Many chemical sensors produce weak signals, despite the fact that they transmit crucial information that has the potential to direct diagnoses and treatments. In fact, medical professionals frequently need to take a sample (blood, sweat, or saliva) and run it through sophisticated laboratory equipment in order to interpret these signals. This equipment is typically pricey and may even be off-site. Additionally, it may take an agonizingly long time for results to appear.
The goal of Rivnay’s team is to detect and amplify these undetectable signals without ever leaving the body.
Aptamers, single DNA strands engineered to bind to particular targets, have been used by other researchers to investigate electrochemical sensors for biosensing. Aptamers function as an electronic switch after successfully attaching to a target of interest because they fold into a new structure that initiates an electrochemical signal. However, when used alone, aptamers frequently produce weak signals that are extremely vulnerable to noise and distortion if testing is not done in a controlled and ideal environment.
In order to get around this problem, Rivnay’s team created an electrochemical transistor-based sensor with a new architecture that can detect and amplify the weak biochemical signal, in addition to adding an amplifying component to a conventional electrode-based sensor. The electrode in this new device is used to detect a signal, but the transistor nearby is solely responsible for amplification. A built-in, thin-film reference electrode was also added by the researchers to increase the stability and dependability of the amplified signals.
“We combine the local amplification capability of the transistor with the reference you get from well-proven electrochemical methods,” Ji said. We can both measure aptamer binding steadily and amplify it locally, which is the best of both worlds.”.
Rivnay’s team used a common cytokine, a class of signaling protein involved in immune response regulation and tissue repair and regeneration, to validate the new technology. Researchers can determine how quickly a wound is healing, whether a new infection is present, and whether additional medical interventions are necessary by measuring the concentration of specific cytokines close to the wound.
Rivnay and his team were able to increase the signal of the cytokines in a series of experiments by three to four orders of magnitude in comparison to conventional electrode-based aptamer sensing techniques. Rivnay claims that the technology should be able to amplify signals from any molecule or chemical, including antibodies, hormones, or drugs, where the detection scheme uses electrochemical reporters, even though it performed well in experiments to sense cytokine signaling.
According to Rivnay, “this approach is generally applicable and doesn’t have a specific use case.”. “The big vision is to incorporate our concept into wearable or implantable biosensors that can detect an issue and then take appropriate action.”.
“Organic electrochemical transistors as on-site signal amplifiers for electrochemical aptamer-based sensing” is the title of the study.
More information: Xudong Ji et al, Organic electrochemical transistors as on-site signal amplifiers for electrochemical aptamer-based sensing, Nature Communications (2023). DOI: 10.1038/s41467-023-37402-2
