Validation of Heterophase RNA Analysis with the Use of a Silicon-on-Insulator Biosensor

The analysis of nucleic acids remains to be a topical trend in the development of medical diagnostics. Contemporary ultrasensitive diagnostic systems provide the conversion of a specific interaction into a hardwarely-detectable signal in the course of analysis. An example of such diagnostic devices is silicon-on-insulator (SOI) biosensors of field-effect transistors (FET). In this study, glass surfaces are used (as a Si/SiO₂ surface for a SOI biosensor) for the optimization and validation of all analysis stages. The efficient immobilization of electroneutral analogs of oligonucleides onto a Si/SiO₂surface after the activation of Si-OH groups with 3-glycidoxypropyltrimethoxysilane or carbonyldiimidazole is demonstrated. In the presence of salt at a low concentration or with no salt, the possibility of detecting an RNA target on model glass surfaces in the parallel analysis regime is shown. The regeneration of the Si/SiO₂ surface of sensors for repeated analysis and the stability of sensors under long-term storage are also demonstrated.