Heart failure is a significant global health issue and poses a higher risk for individuals without access to healthcare facilities. To address this, a group of researchers is working on a portable screening method that could allow heart failure testing to be conducted at home. They have developed a prototype of an electrochemical biosensor that can analyze two important heart failure biomarkers using just a small amount of saliva in as little as 15 minutes.
Heart failure is a major cause of death around the globe and can be particularly dangerous for those lacking access to medical support. In response, a team of researchers is focused on transforming heart failure screening from laboratory settings to at-home use. Their innovative electrochemical biosensor prototype, which is similar to a clear lateral flow test for COVID-19, is capable of assessing two crucial heart failure biomarkers from just a droplet of saliva in about 15 minutes.
Trey Pittman, a graduate student at Colorado State University, plans to present his team’s findings at the American Chemical Society’s fall meeting.
“Our device is designed for individuals at high risk for heart failure who have limited access to hospitals or testing labs,” Pittman explains. “This project is particularly significant to me because I come from Mississippi, a state with one of the highest heart failure mortality rates in the U.S. It’s important to tackle health inequalities in rural and underserved areas,” he emphasizes.
Heart failure occurs when the heart muscle weakens and is unable to distribute enough oxygenated blood throughout the body. Currently, the most reliable method for diagnosing heart failure is through a blood test conducted twice a year by a healthcare professional, which measures the levels of B-type natriuretic peptide (BNP), a marker indicating that the heart is under strain.
However, advancements in point-of-care technology could democratize access to healthcare by enabling simple, at-home saliva tests for heart failure screening. Such tests would allow individuals to monitor their heart health every few weeks instead of waiting six months, as suggested by Pittman. The development of portable saliva tests for heart health has been hindered by complex manufacturing processes and insufficient data correlating multiple biomarkers.
Working to overcome these obstacles, Pittman and his colleagues have made promising advancements in their economical biosensor prototype, termed the electrochemical capillary-driven immunoassay (eCaDI). The team, in conjunction with researchers from Colorado State University and Griffith University in Australia, has combined two of their earlier technologies: a microfluidic device for saliva and a biosensor targeting the biomarker proteins Galectin-3 and S100A7, finding that their levels in saliva relate to heart failure conditions.
The eCaDI is constructed with five layers, resembling a club sandwich: three layers of transparent, flexible plastic bonded with alternating double-sided adhesive layers.
- The top plastic layer features small holes for saliva sample introduction.
- The center plastic layer includes laser-cut channels leading to blotting paper squares that help draw saliva through them.
- Encased between the outer plastic layers are reagent pads made of glass fiber that react with saliva, allowing for the measurement of Galectin-3 and S100A7 when an electrical current is applied.
- The bottom plastic layer contains carbon ink electrodes that are screen-printed onto its surface.
- Two electrodes, powered by small wired clamps connected to a device known as a potentiostat, initiate the chemical reaction on the reagent pads.
“Assembling the devices is straightforward,” Pittman notes. “We can produce five units in about 20 to 30 minutes.” Each eCaDI is designed for one-time use and costs roughly $3.00 to produce; the reusable potentiostat retails for about $20.
During demonstrations, the research team added specific levels of heart failure biomarkers to standardized human saliva samples to test the device. Their findings indicate that the eCaDI successfully identified Galectin-3 and S100A7 levels in the saliva samples. “These demonstrations represent an initial achievement towards creating a reliable and non-invasive electrochemical sensor for heart failure biomarkers,” states Pittman. The next phase involves testing the eCaDI with healthy individuals and those with heart failure at Griffith University.
“This technology could serve as a foundation for developing saliva tests for various diseases,” Pittman suggests. “I believe it holds the potential to positively impact many lives, particularly those in underserved communities, helping them live longer and healthier lives.”
This research received funding from the U.S. National Institutes of Health.
