Gene probe coated piezoelectric biosensors for biochemical analysis

A new method has been developed to monitor DNA hybridization by using piezoelectric (PZ) crystal biosensor system. AT-cut crystals, with a basic resonant frequency of 9 MHz, were modified by a series of surface pretreatment as followings: gold plated, anoidical oxidation and gamma-aminopropyltriethoxysilane treatment. Single stranded DNA probe was electro-blotted onto the surface of crystal electrodes. The DNA probe was further fixed on the crystal surface by UV crosslinking. The crystal sensor is dipped into the hybridization solution and the surface mass increase, caused by hybridization, is measured by the decrease in the resonant frequency of the crystal. The potential capability to obtain qualitative as well as quantitative information on a sample through such an DNA hybridization assay makes this technique an attractive alternative to conventional analytical techniques that require use of radio-isotope.