A piezoelectric immunosensor for hepatitis viruses

A reusable piezoelectric immunosensor was used for the detection of the human hepatitis viruses type A and type B. The virus specific monoclonal antibodies were immobilized via protein A onto a 16-MHz AT-cut crystal. Binding of the virions resulted for 1 × 105 to 1 × 1010 viruses in solution in a linear frequency change. The detection limit of our system is 1 × 105 virions and the experimental error is 8%. When the modified crystal was stored dry over silica gel blue at room temperature, the long term stability of our system was four weeks. Under these conditions, the coated crystal can be used ten times without detectable loss of activity. These results are compared with those for an enzyme-linked immunosorbent assay (ELISA).