A Love-wave biosensor using nucleic acids as ligands

A Love-wave biosensor array has been designed by coupling aptamers to the surface of a Love-wave sensor chip. The sensor chip consists of five single sensor elements and allows label-free, real-time, and quantitative measurements of protein and nucleic acid binding events in concentration-dependent fashion. The biosensor was calibrated for human α-thrombin and HIV-1 Rev peptide by binding fluorescently labelled molecules and correlating the mass of the bound molecules to fluorescence intensity. Detection limits of approximately 75 pg/cm2 were obtained, and analyte recognition was specific. The sensor can easily be regenerated by simple washing steps. We further demonstrate the versatile applicability of the sensor by immobilizing single-stranded DNA (ssDNA) for the detection of the corresponding counter-strand.