Immobilization of DNA probes on a high frequency piezoelectric biosensor

Abstract

In recent years, researchers have taken to biosensors as effective tools for detection due to their portability, low-cost, fast response, and practicality. Piezoelectricity gave way to quartz crystal microbalances (QCM), of which high-frequency QCMs (HFF-QCM 100MHz) are still being researched. In this paper, we use DNA immobilization on a HFF-QCM via self-assembled monolayers (SAM) technique. Immobilization was initially verified with ATR-FTIR. Then, DNA was immobilized in real time on the HFF-QCM crystals. A variation in the phase of the signal suggests fixation of DNA to the surface, in accordance with ATR-FTIR results. A density of 629 ng/cm2 was computed. Also, a positive correlation between immobilized DNA and DNA concentration, and the appearance of a saturation point between 1 and 5 μM were shown after analysis of different DNA concentrations.