The fusion protein technique was used to prepare an artificial polyfunctional protein from calmodulin (CaM) and glutathione S-transferase (GST). The fusion protein was designed, expressed, purified, and then assembled to the glutathione self-assembled gold surface. The protein assembly was confirmed through enzyme binding assay and enzyme immunoassay. Specific binding of the fusion protein to glutathione self-assembled on the gold surface was assessed via a quartz crystal microbalance (QCM). The fusion protein was reversibly adsorbed and desorbed by the competitive binding of glutathione present in a solution, thus showing that the binding of the fusion protein was specific and had a highly oriented molecular configuration. (C) 1997 Elsevier Science B.V.