Hydrogen Peroxide Sensing Based on Inner Surfaces Modification of Solid-State Nanopore

There are many techniques for the detection of molecules. But detection of molecules through solid-state nanopore in a solution is one of the promising, high-throughput, and low-cost technology used these days. In the present investigation, a solid-state nanopore platform was fabricated for the detection of hydrogen peroxide (H₂O₂), which is not only a label free product but also a significant participant in the redox reaction. We have successfully fabricated silicon nitride (Si₃N₄) nanopores with diameters of ~50 nm by using a focused Ga ion beam, the inner surface of the nanopore has been modified with horseradish peroxidase (HRP) by employing carbodiimide coupling chemistry. The immobilized HRP enzymes have ability to induce redox reactions in a single nanopore channel. Moreover, a real-time single aggregated ABTS^•+ molecular translocation events were monitored and investigated. The designed solid-state nanopore biosensor is reversible and can be applied to detect H₂O₂ multiple times.