Nanogap for wireless fluidics and dielectric manipulations

Abstract

An inevitable response to the SARS-CoV-2 pandemic and the threat of similar future global calamities is an advancement in public health protocols--including testing and early diagnostics. This technology will require rapid detection of low-concentration material and should exist within a simple framework that is portable and cheap to manufacture. Nanotechnology can enhance detection sensitivity by focusing the sensing volumes of measurement signals to the size of the analyte. However, adequate transport of the analytes to these small volumes is often not addressed and can greatly limit detection. Diffusion transport, being the state-of-the-art, is not rapid and results in random analyte placement. In this work, nanostructures are engineered to serve a dual role to expedite analyte transport and support biosensing. Specifically, nanogap electrodes, surface-tension-mitigating geometry, and resonant circuitry are combined to rapidly focus biological particles and the liquid medium itself to the most sensitive regions for fluorescent imaging, vibrational spectroscopy, and impedance-based sensing. Additionally, these structures can facilitate practical actions such as filtering, mixing, and chemical labeling, and be powered using a sub-5 volt, wireless, radio-frequency signal (with a smartphone demonstration included). This design offers a simple approach for analyte transport to complement the advantages of sensitive nanotechnology while being portable, easily manufacturable, and as accessible as one's front pocket.