Noise spectroscopy analysis for estimation of specific biomolecule in complex mixture using solid state nanopore

This paper presents noise spectroscopy analysis of the current traces recorded in a functionalized silicon oxide nanopore in presence of specific antigen (Hep-B), non-specific antigen(BSA) and their mixture for the first time. It is observed that though the on and off dwell times can differentiate the presence of only specific and non-specific antigen, approximate quantification of the specific antigen in complex mixture becomes almost impossible either from the magnitude or the dwell times of the current blockade events, for a receptor-ligand pair with low association constants. On the contrary, noise spectroscopy analysis shows a Lorentzian spectrum in presence of specific antigen with a distinct shift in the roll off frequency between 100 nM Hep-B and a mixture of 10 pM Hep-B with 1 nM BSA.