title: Development of an Optical Nanosensor Incorporating a pH-Sensitive Quencher Dye for Potassium Imaging.
abstract: One of the key challenges in the design of a sensor for measuring extracellular changes in potassium concentration is selectivity against the competing cation, sodium. Here, we present an optode-based nanosensor selective to potassium ions, owing to the addition of a pH-sensitive quencher molecule paired with a static fluorophore. The nanosensor was fabricated using emulsification and characterized in solution by absorbance and fluorescence spectroscopy. The resulting nanosensor detected potassium with nearly 1 order of magnitude higher selectivity compared to our chromoionophore-based optode nanosensors. In addition to the improved selectivity, the nanosensor has the following properties required for measurements in a biological environment: (1) a physiologically relevant dynamic range, (2) response to potassium ions at a physiological ionic strength, and (3) response to serum potassium in the presence of fouling biological components. The potassium nanosensor described in this study is envisioned to have application in cellular imaging and drug screening.
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University , Boston, Massachusetts 02115, United States.
authors.forename: Ali
authors.initials: A
authors.lastname: Sahari
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University , Boston, Massachusetts 02115, United States.
authors.forename: Timothy T
authors.initials: TT
authors.lastname: Ruckh
authors.affiliation: Berry and Associates, Inc. , Dexter, Michigan 48130, United States.
authors.forename: Richard
authors.initials: R
authors.lastname: Hutchings
authors.affiliation: Department of Pharmaceutical Sciences, Northeastern University , Boston, Massachusetts 02115, United States.
authors.forename: Heather A
authors.initials: HA
authors.lastname: Clark
mesh_terms: D004355:Drug Stability; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods*; D055095:Optics and Photonics; D011188:Potassium / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005456:Fluorescent Dyes; D011188:Potassium