Silicon Nitride Nanopores for Nanoparticle Sensing

In recent years, nanopore has attracted broad attention as an essential technique for DNA sequencing and nanoparticle sensing. This work presented a fundamental study of nanoparticle translocation through silicon nitride nanopores. Since particles with rather high charge to mass ratio, such as DNA and proteins, have been widely studied, there was still little information about the translocation behavior of nanoparticles with low charge/mass ratio. However, these nanoparticles include viruses and colloids are important potential sample for nanopore sensing technique. In order to screen nanoparticles' size, concentration, surface property by apply silicon nitride nanopores, and fulfill specific recognition which could be applied in laboratory medicine and environmental monitoring, optimal experimental conditions needed to be confirmed. In this paper, polystyrene (PS) bead was used as an example to provide reference towards this condition. The effects of nanopore/nanoparticle diameter ratio and bias voltage on sensing results were analyzed in this work. We found that lower precision accuracy might be demonstrated by the larger pore (120 nm) while the translocation velocity tended to be slowed down. By increasing the bias voltage could favor the detection productiveness. In spite of the intense interest, the baseline fluctuations and vague event bounds aggravated are far from understood.