title: Nanopore detection of copper ions using a polyhistidine probe.
abstract: We report a stochastic nanopore sensing method for the detection of Cu(2+) ions. By employing a polyhistidine molecule as a chelating agent, and based on the different signatures of the events produced by the translocation of the chelating agent through an α-hemolysin pore in the absence and presence of target analytes, trace amounts of copper ions could be detected with a detection limit of 40 nM. Importantly, although Co(2+), Ni(2+), and Zn(2+) also interacts with the polyhistidine molecule, since the event residence times and/or blockage amplitudes for these metal chelates are significantly different from those of copper chelates, these metal ions do not interfere with Cu(2+) detection. This chelating reaction approach should find useful application in the development of nanopore sensors for other metal ions.
authors.affiliation: Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S Dearborn St, Chicago, IL 60616, USA.
authors.forename: Guihua
authors.initials: G
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.forename: Yujing
authors.initials: Y
authors.lastname: Han
authors.forename: Shuo
authors.initials: S
authors.lastname: Zhou
authors.forename: Xiyun
authors.initials: X
authors.lastname: Guan
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D003300:Copper / Q000737:chemistry / Q000302:isolation & purification*; D006460:Hemolysin Proteins / Q000737:chemistry; D006639:Histidine / Q000737:chemistry*; D007477:Ions / Q000737:chemistry / Q000302:isolation & purification*; D008670:Metals / Q000737:chemistry; D015335:Molecular Probes; D058608:Nanopores
chemical_list: D006460:Hemolysin Proteins; D007477:Ions; D008670:Metals; D015335:Molecular Probes; C033223:polyhistidine; D006639:Histidine; D003300:Copper
keywords: Biosensor; Chelation; Copper; Nanopore sensing; Polyhistidine