Development of a multi-channel immunosensor for determnination of serum hepatic fibrosis markers

In this study, basing on electrochemistry and MEMS technology we develop a novel biosensor with multi channels to detect three markers (hyaluronic acid (HA), Laminin (LN), type IV collagen (IV-C) ) so as to evaluate the liver disease. With MEMS technology, a chip including a CE, a RE and 6 gold electrodes is fabricated for detection of at most 6 markers simultaneously. Different antibodies of serum markers are embedded in poly(o-phenylenediamine) to form semi-insulated membranes on the gold electrodes, separately by electrochemical polymerization. It is grounded on a mechanism of detecting the variation of the peak current caused by the immunoreactions between the markers and their corresponding antibodies. Concentrations of HA, LN and IV-C in 140 samples are tested both by the sensor and RIA, namely, sensor group and RIA group. Compared the two groups of results, it is found that the two measures have similar sensitivities and consistency while the sensor has significantly reduced the response time as well as the cost. The coefficients of variation of the sensor are less than 20% for both inter and intra-assay with error less than 20%, while for RIA, coefficients of variation for intra-assay less than 10% and inter-assay less than 15% with error less than 20%