A general anion-sensing platform is reported based on a portable and cost-effective ion-selective optode and a smartphone detector equipped with a color analysis app. In contrast to traditional anion-selective optodes using a hydrophobic polymer and/or plasticizer to dissolve hydrophobic sensing elements, the new optode relies on hydrophilic cellulose paper. The anion ionophore and a lipophilic pH indicator are inkjet-printed and adsorbed on paper and form a "dry" hydrophobic sensing layer. Porous cellulose sheets also allow the sensing site to be modified with dried buffer that prevents any sample pH dependence of the observed color change. A highly selective fluoride optode using an AlIII -porphyrin ionophore is examined as an initial example of this new anion sensing platform for measurements of fluoride levels in drinking water samples. Apart from Lewis acid-base recognition, hydrogen bonding recognition is also compatible with this sensing platform.
A general anion-sensing platform is reported based on a portable and cost-effective ion-selective optode and a smartphone detector equipped with a color ann class="Chemical">alysis app. In contrast to traditional anion-selective optodes using a hydrophobic polymer and/or plasticizer to dissolve hydrophobic sensing elements, the new optode relies on hydrophilic cellulose paper. The anion ionophore and a lipophilic pH indicator are inkjet-printed and adsorbed on paper and form a "dry" hydrophobic sensing layer. Porous cellulose sheets also allow the sensing site to be modified with dried buffer that prevents any sample pH dependence of the observed color change. A highly selective fluoride optode using an AlIII -porphyrin ionophore is examined as an initial example of this new anion sensing platform for measurements of fluoride levels in drinking water samples. Apart from Lewis acid-base recognition, hydrogen bonding recognition is also compatible with this sensing platform.
Authors: Yuanyuan Yang; Eka Noviana; Michael P Nguyen; Brian J Geiss; David S Dandy; Charles S Henry Journal: Anal Chem Date: 2016-12-12 Impact factor: 6.986
Authors: Guoxin Rong; Eric H Kim; Yi Qiang; Wenjun Di; Yiding Zhong; Xuanyi Zhao; Hui Fang; Heather A Clark Journal: ACS Sens Date: 2018-10-25 Impact factor: 7.711