Solid-State Nanopore Detection of Protein Complexes: Applications in Healthcare and Protein Kinetics

Protein conjugation provides a unique look into many biological phenomena and has been used for decades for molecular recognition purposes. In this study, the use of solid‐state nanopores for the detection of gp120‐associated complexes are investigated. They exhibit monovalent and multivalent binding to anti‐gp120 antibody monomer and dimers. In order to investigate the feasibility of many practical applications related to nanopores, detection of specific protein complexes is attempted within a heterogeneous protein sample, and the role of voltage on complexed proteins is researched. It is found that the electric field within the pore can result in unbinding of a freely translocating protein complex within the transient event durations measured experimentally. The strong dependence of the unbinding time with voltage can be used to improve the detection capability of the nanopore system by adding an additional level of specificity that can be probed. These data provide a strong framework for future protein‐specific detection schemes, which are shown to be feasible in the realm of a ‘real‐world’ sample and an automated multidimensional method of detecting events. A nanopore platform is shown to detect various sub‐populations of protein‐protein complexes as well as dissociate freely translocating proteins generating unique current signatures. The proposed method of locally unbinding protein molecules allows enhancement of the specificity of diagnostic nanopore sensors as well as the abiltiy to study the recently unbound state of a protein. These applications underscore the label‐free, inexpensive, electrical detection scheme offered by nanopore‐based devices.