Kinetics of hybridization of interfacial RNA homopolymer studied by thickness-shear mode acoustic wave sensor

The impedance response of RNA homopolymer hybridization on the electrode-solution interface of thickness shear mode acoustic wave sensors has been examined on a real-time basis by network analysis. The effects of blocking agents conventionally used to avoid nonspecific adsorption, solution ionic strength and temperature on the rate of interfacial hybridization have been examined quantitatively in terms of a pseudo-first order effective rate constant. A hybridization mechanism involving transport of RNA probe molecules in solution followed by duplex formation is proposed. The results suggest that the use of blocking agents is not necessary and that the biosensor is capable of the direct detection of hybridization in the present of nonspecific adsorption. (C) 1997 Elsevier Science Limited.