ABSTRACT
Single nanopore current pulse method is a new, rapid and simple detection method, which is promising for single-molecule DNA sequencing and bio-sensing. Due to the short duration and the low current amplitude of the pulses caused by molecular translocation under normal conditions, pulse detection system with fast response and high sensitivity is required. In this work, based on a lab-established pulse detection system, the effect of protamine in the regulation of single-stranded (ssDNA) current pulses with α-hemolysin (α-HL) single nanopore interface was investigated. Experimental results showed that the pulses positive charged protamine and negative ssDNA probes were both well observed with the established system, and both the pulse amplitude and duration of ssDNA were increased as a result of interaction with protamine. This study provides a way to improve the resolving power of current pulses based on molecular interactions.