A reflectometric ion sensor for potassium based on acrylic microspheres

SENSORS AND ACTUATORS B-CHEMICAL

卷:191

Article

Yew, Pei Ling¹  Heng, Lee Yook¹ 

[1] Univ Kebangsaan Malaysia, Fac Sci & Technol, Sch Chem Sci & Food Technol, Bangi 43600, Selangor Darul, Malaysia

关键词: Nile Blue;    Acrylic microspheres;    Valinomycin;    Optical ion sensor;    Reflectance measurement;   

DOI  :  10.1016/j.snb.2013.10.069

来源: Elsevier

【 摘 要 】

A K+ ion-sensitive optical sensor based on Nile Blue (chromoionophore ETH5294) incorporated into poly(n-butyl acrylate) [poly(nBA)] microspheres was successfully developed. A combination of acrylic spheres and optical reflectometry had enhanced the sensing performance of the optical K+ ion sensor, as the former provides large surface area for better loading capacity and higher reaction rate, while the latter offers simple and rapid measurements. The sensing mechanism involves ion-exchange reaction, which occurs at the surface of the microspheres where influx of K+ ions and efflux of H+ ions take place. The sensor response was a result of the total deprotonation of chromoionophore immobilized within poly(nBA) microspheres in response to the formation of K+ ion-ionophore complex. The change of the response in the presence of K+ ions was studied via reflectance spectroscopy using an optical fibre probe. The K+ ion sensor based on these microspheres exhibited sensitivity slope of 43.15 AIntensity/decade (R-2 = 0.961) in a range 0.01-1000 mM of KCl with a lower detection limit of 0.01 mM. Sensor response time was 10 min with good reproducibility (relative standard deviation, %RSD = 5.71). Analysis of urine samples for K+ ions gave 87-115% recovery and the results were comparable with established method for K+ ions analysis. Leaching tests and life time study revealed that acrylK(+) microspheres worked well as an immobilization matrix for hydrophob K+ chromoionophore. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

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