title: Simultaneous stochastic sensing of divalent metal ions.
abstract: Stochastic sensing is an emerging analytical technique that relies upon single-molecule detection. Transmembrane pores, into which binding sites for analytes have been placed by genetic engineering, have been developed as stochastic sensing elements. Reversible occupation of an engineered binding site modulates the ionic current passing through a pore in a transmembrane potential and thereby provides both the concentration of an analyte and, through a characteristic signature, its identity. Here, we show that the concentrations of two or more divalent metal ions in solution can be determined simultaneously with a single sensor element. Further, the sensor element can be permanently calibrated without a detailed understanding of the kinetics of interaction of the metal ions with the engineered pore.
authors.affiliation: Department of Medical Biochemistry & Genetics, The Texas A&M University System Health Science Center, College Station, TX 77843-1114, USA. obraha@medicine.tamu.edu
authors.forename: O
authors.initials: O
authors.lastname: Braha
authors.forename: L Q
authors.initials: LQ
authors.lastname: Gu
authors.forename: L
authors.initials: L
authors.lastname: Zhou
authors.forename: X
authors.initials: X
authors.lastname: Lu
authors.forename: S
authors.initials: S
authors.lastname: Cheley
authors.forename: H
authors.initials: H
authors.lastname: Bayley
mesh_terms: D001665:Binding Sites; D015374:Biosensing Techniques; D002104:Cadmium / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D003198:Computer Simulation; D004563:Electrochemistry / Q000379:methods*; D007477:Ions; D008564:Membrane Potentials; D008670:Metals / Q000737:chemistry*; D016297:Mutagenesis, Site-Directed; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D013269:Stochastic Processes; D013997:Time Factors; D015032:Zinc / Q000737:chemistry
chemical_list: D007477:Ions; D008670:Metals; D010455:Peptides; D002104:Cadmium; D003035:Cobalt; D015032:Zinc