Detection of single gold nanoparticle in liquid with nanopore-integrated microwave resonators

Here, we propose a nanopore integrated microwave resonator to detect single nanoparticles in real time. In contrast to existing nanopore-sensors relying on detection techniques like resistive pulse sensing, and current-voltage measurements, the presented coplanar-waveguide sensor detects the passage of gold nanoparticles through a nanopore on a thin film membrane. Resonance frequency of the sensor, which is around 7 GHz, is tracked by a custom-built close loop circuitry. Gold nanoparticles are electro kinetically driven through the pore: as each nanoparticle passed the pore, it induces a shift in the resonance frequency of the resonator. The presented method is not limited by the specific design of the pore, alleviating the stringing condition on pore size and shape with respect to the target analyte.