Electrochemical immunosensor for the quantification of galectin-3 in saliva

Heart failure (HF) is an emerging epidemic and remains a major clinical and public health problem. Advances in the healthcare management of HF may lead to lower morbidity and mortality rates but require diagnostics to guide the process. Current diagnostics/prognostics approaches rely on expensive equipment, centralized facilities and trained personnel, marginalizing healthcare access in developing countries and rural communities. These issues have led researchers to focus on developing portable and affordable diagnostics that can be deployed at the point-of-care (POC). Typically, HF biomarkers are measured in blood not saliva. Recently, our team correlated concentrations of salivary Galectin-3 (Gal-3) to outcomes in patients with HF. We have developed an analytical device which consists of an immunoassay based on a screen-printed carbon electrode (SPCE) to quantify Gal-3 levels in saliva samples. Using 10 mu L of saliva, the proposed electrochemical immunoassay achieved a concen-tration dependent signal response in the clinically relevant range with a limit of detection of 9.66 ng/mL. In addition, the storage stability of the modified electrode was investigated, and only a 10.9 % loss in current response over a 35-day period. The results of the immunoassay on the modified SPCEs suggest validity as a POC biosensor system for the management of HF.