title: Reversible cation response with a protein-modified nanopipette.
abstract: The calcium ion response of a quartz nanopipette was enhanced by immobilization of calmodulin to the nanopore surface. Binding to the analyte is rapidly reversible in neutral buffer and requires no change in media or conditions to regenerate the receptor. The signal remained reproducible over numerous measurements. The modified nanopipette was used to measure binding affinity to calcium ions, with a K(d) of 6.3 ± 0.8 × 10(-5) M. This affinity is in good agreement with reported values of the solution-state protein. The behavior of such reversible nanopore-based sensors can be used to study proteins in a confined environment and may lead to new devices for continuous monitoring.
authors.forename: Boaz
authors.initials: B
authors.lastname: Vilozny
authors.forename: Paolo
authors.initials: P
authors.lastname: Actis
authors.forename: R Adam
authors.initials: RA
authors.lastname: Seger
authors.forename: Queralt
authors.initials: Q
authors.lastname: Vallmajo-Martin
authors.forename: Nader
authors.initials: N
authors.lastname: Pourmand
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D002118:Calcium / Q000032:analysis* / Q000378:metabolism; D002147:Calmodulin / Q000737:chemistry / Q000378:metabolism*; D002412:Cations / Q000032:analysis / Q000378:metabolism; D055767:Immobilized Proteins / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods; D011485:Protein Binding; D011791:Quartz / Q000737:chemistry
chemical_list: D002147:Calmodulin; D002412:Cations; D055767:Immobilized Proteins; D011791:Quartz; D002118:Calcium