title: Surface Modified Thread-Based Microfluidic Analytical Device for Selective Potassium Analysis.
abstract: This paper presents a thread-based microfluidic device (μTAD) that includes ionophore extraction chemistry for the optical recognition of potassium. The device is 1.5 cm × 1.0 cm and includes a cotton thread to transport the aqueous sample via capillary wicking to a 5 mm-long detection area, where the recognition chemistry is deposited that reaches equilibrium in 60 s, changing its color between blue and magenta. A complete characterization of the cotton thread used as well as the sensing element has been carried out. The imaging of the μTAD with a digital camera and the extraction of the H coordinate of the HSV color space used as the analytical parameter make it possible to determine K(I) between 2.4 × 10(-5) and 0.95 M with a precision better than 1.3%.
authors.affiliation: Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, 18071, University of Granada , Granada, Spain.
authors.forename: Miguel M
authors.initials: MM
authors.lastname: Erenas
authors.affiliation: Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, 18071, University of Granada , Granada, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: de Orbe-Payá
authors.affiliation: Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, 18071, University of Granada , Granada, Spain.
authors.forename: Luis Fermin
authors.initials: LF
authors.lastname: Capitan-Vallvey