Tailoring the Hybridization Density of DNA Biosensors through Tunable Surface Functionalization

DNA biosensors are promising candidates for the development of point-of-care diagnosis methods. They can be inserted in microfluidic platforms, are often non-expensive, and can be produced for a variety of targeted analytes. However, their development faces several challenges, some of which arise from their surface design. Among the characteristics which affect the binding efficiency of DNA probes to their targeted genes, the packing density and lateral spacing of the probe sequences must be controlled to provide enough binding sites and avoid crowding effect. It has also been demonstrated that increasing the space between the probe and the substrate can enhance the sensitivity of the sensing surface. Herein, we describe a methodology to control the vertical distance between DNA probes and a glass support, and lateral spacing between the probes. Such functionalization strategy could help the development of sensing surface with high hybridization density, and therefore high sensitivity.