Biosensor technology could measure two heart failure biomarkers from saliva
A new biosensor prototype, which is a simple, at-home saliva test, could measure two biomarkers for heart failure providing a diagnostic tool for individuals who don’t have access to centralized facilities.
Researchers from Colorado State University (CO, USA) have created a point-of-care electrochemical biosensor prototype that measures the levels of two heart failure biomarkers. The research was presented at the American Chemical Society (18−22 August 2024; CO, USA). Using a drop of saliva and taking just 15 minutes, the prototype is simple, non-invasive and easy-to-use, combatting the current obstacles to diagnosis.
Globally, heart failure is the leading cause of death and is especially dangerous for those who cannot access medical facilities. Current diagnostics require expensive equipment, specialized facilities, trained staff and invasive sampling, making it inaccessible to patients in marginalized communities. Portable saliva tests provide a solution to these obstacles, but they have been hindered by complex manufacturing techniques and the ability to only detect one biomarker.
At present, the gold standard for diagnosing heart failure is a blood test conducted twice a year at a healthcare facility. The test indicates if the heart is working too hard by measuring levels of B-type natriuretic peptide.
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To make heart failure screening more accessible, the researchers are proposing a saliva test that could be administered by patients every few weeks. Their device is a low-cost biosensor prototype called an electrochemical capillary-driven immunoassay (eCaDI) that detects the two biomarkers Galectin-3 and S100A7.
The eCaDI device is comprised of five layers. The top layer is made of plastic and has holes for loading the saliva samples. The middle plastic layer has laser-cut channels with blotting paper at the end that draw saliva from the loading site through the channels. Between the next two plastic layers are glass fiber reagent pads that react with the saliva to measure the two biomarkers when it receives an electrical current. The final layer of plastic has carbon ink electrodes on its surface.
These electrodes receive a signal from an external source, called a potentiostat, which then drives the chemical reaction to occur in the reagent pads. The device is cheap and easy to assemble.
To test the device, the researchers added the two biomarkers to human saliva samples to see if eCaDI would detect them and it did. The next step in the research is to test the device on healthy individuals and patients with heart failure.
Trey Pittman, a graduate student from Colorado State University, commented: “This work may provide a starting point for new saliva testing platforms for other diseases. It’s a technology that I think could end up helping a lot of people — especially the underserved — live longer, healthier lives.”
