A saliva-based sensor for monitoring heart failure

A small, inexpensive sensor may be able to help people with heart failure monitor their condition without visiting a hospital.

Trey Pittman, a graduate student in Chuck Henry’s lab at Colorado State University, is developing a saliva-based microfluidic sensor to test for two biomarkers: galectin-3 and S100A7. Pittman presented this research at the ACS Fall 2024 meeting in Denver in the Division of Analytical Chemistry.

The test is designed to monitor the condition of people who have already been diagnosed with heart failure. The two biomarkers have previously been found to be elevated in people with heart failure, and patients with higher concentrations of galectin-3 were more likely to have poorer outcomes, including hospitalization and death (Clin. Res. Cardiol. 2020, DOI: 10.1007/s00392-019-01557-0 and Biomolecules 2019, DOI: 10.3390/biom9120766).

Heart failure isn’t an acute event that happens at one time; rather, it’s a chronic condition in which the heart loses its ability to effectively pump blood throughout the body over time. Heart failure isn’t curable, but it can be managed—and monitoring these biomarkers may help people make the changes or get the care they need to keep their condition under control.

Once a saliva sample is loaded onto the device, capillary action directs the sample to the sensor area. A potentiostat then measures the output of an oxidation reaction between galectin-3 and antibodies on the sensor.

A smartphone could power this potentiostat, and an app would analyze the results. The entire device, potentiostat included, is estimated to cost about $23 to manufacture. The sensor alone is estimated to cost about $3 to manufacture—but it is a single-use device.

Maral Mousavi, one of the session organizers and an assistant professor at the University of Southern California who was not involved with the research, said that there is “a lot of potential to actually commercialize this” but that “commercialization of a device is always challenging.” She noted that it’s unknown how long the antibodies on the sensor will be stable sitting on a shelf.

While the goal is to have patients sent home from the clinic with this device, it may be difficult to ensure that people use it correctly. Patients would need to control the amount of saliva and mix it with a buffer. But Mousavi also noted that the public is a lot more educated about how to use at-home tests because of the COVID-19 pandemic.

“My vision is that it’s going to really help the rural areas that don’t have centralized lab facilities or trained personnel,” Pittman added. “I have family members that have had to travel a few hours to the capital [city] or to other treatment facilities just to get quality care for different diseases, and I think it shouldn’t be that way. It should be something that we can all have access to.”