Surface modification of SOI sensors for the detection of RNA biomarkers

A new type of surface modification of multichannel sensors on a silicon-on-insulator base, which includes the use of a carbonyldiimidazole bifunctional reagent for the formation of an interfacial layer instead of modified silanes and probes for the specific detection of fragments of matrix troponin ribonucleic acid (analyte) as a marker of the cardiac infarction, is proposed. The influence of passivating the sensor surface activated by carbonyldiimidazole with glycine and aminoethanol at the final modification state on the response of sensors and the level of the background signal is investigated. It is shown that the proposed type of surface modification with glycine treatment provides a highly specific response of $\sim$60% in the case of a picomolar analyte concentration in the solution. Different mechanisms are responsible for an increase in the response and sensor specificity during analyte detection after passivation by glycine and aminoethanol.