Electrochemical biosensor array for liver diagnosis using silanization technique on nanoporous silicon electrode

An electrochemical biosensor array system was fabricated for the diagnosis and monitoring of liver diseases. Analysis on this array system with multiple samples was performed for point-of-care testing or home-use applications. Cholesterol, bilirubin and aminotransferases present in the serum are well-known biomarkers for liver diseases. For this study, we describe our biosensor array system consisting of cholesterol, bilirubin and glutamate sensors. To immobilize sensing enzymes on the array system, we employed a silanization technique. We observed that porous silicon layers formed on each working electrode notably increase the effective surface area. Sensing electrodes were placed in sampling wells to minimize the cross-interference effect so that multiple sampling would be possible with a low noise current. Compared with traditional analyte measurement procedures, our novel analytical device demonstrated acceptable sensitivities for the analyses of multiple samples and analytes without a marked cross-interference effect. The device sensitivities observed were 0.2656 mu A/mM for cholesterol, 0.15354 mA/mM for bilirubin, 0.13698 mu A/(U/l) for alanine aminotransferase (ALT) and 0.45439 mu A/(U/l) for aspartate aminotransferase (AST).