(98c) Determining the Levels of Key Liver Biomarkers Using An Ir/C Printed Biosensor for the Detection of Liver Disease

A growing problem in today's population is the increasing number of individuals suffering from forms of liver disease. Detection and diagnosis of diseases, such as hepatitis and cirrhosis, would benefit from the development of a rapid and easy detection method. A method would be especially vital in economically disadvantaged countries such as Egypt, Rwanda and Tanzania, where more than 10% of the population is suffering from some form of liver disease.

When an individual becomes infected with liver disease changes in a series of chemicals in the body, called biomarkers, are observed. Two particular biomarkers that have shown good clinical correlation to the presence of liver disease are total bile acid and adenosine deaminase activity. By monitoring the levels of these biomarkers in the body it is possible to detection the presence of liver disease, and to some level the type.

The current method for detecting the biomarkers requires the use of a spectrophotometer. While the spectrophotometer serves as an accurate measurement technique, it is ill-suited for being able to process patient samples on-site due to its large physical size, delicate parts and complexity in operation. As an alternative, a low cost, single-use screen-printed iridium/carbon biosensor is proposed. This sensor is able to oxidize both NADH and hydrogen peroxide at the potential +0.27V versus the printed Ag/AgCl reference electrode. Using these sensors, and immobilized enzymes, the specific concentrations of total bile acid and adenosine deaminase could be determined amperometrically. Variables including: pH, temperature and testing media were explored to understand their influence on the current output as related to initial biomarker concentration. Testing results show that the constructed sensors can accurately, and repeatedly, detect the presence of the biomarkers total bile acid and adenosine deaminase. It is believed that these initial results show the sensor to be a promising viable method of detecting liver disease, particularly in those individuals who currently have limited access to medical diagnosis.