Fig. 1

Performing modification process in a single solid-state nanopore channel. a Schematic representation of the covalent attachment of horseradish peroxidase (HRP) to a single nanopore channel via carbodiimide coupling chemistry. The carboxyl (-COOH) groups of HRP was activated by EDC solution, enabling the HRP to react with (-NH₂) generated on the surface of a nanopore chip. b Scheme of the immobilized HRPs hydrogen peroxide sensor, the inner surface of sensor was modified with HRPs. When H₂O₂ and ABTS occurred, the ABTS^•+ produced. The crystal structure of HRP was used with the permission from author [3]