Calcium-selective electrode based on polyaniline functionalized with bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphate

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: Lindfors T, Ivaska A
Publisher: ELSEVIER SCIENCE BV
Publication year: 2001
Journal: Analytica Chimica Acta
Journal acronym: ANAL CHIM ACTA
Volume number: 437
Issue number: 2
Start page: 171
End page: 182
Number of pages: 12
ISSN: 0003-2670
eISSN: 1873-4324


Abstract

A new Ca2+-selecrive polyaoiline (PANI)-based membrane material suitable far all-solid-state-sensor applications is presented. The membrane consists of electrically conducting PANI, bis[4-(1,1,3,3-tetramethylbutyl)phenyl]phosphoric acid (DTMBP-PO4H), dioctyl phenylphosphonate (DOPP) and cationic (tridodecylmethylammonium chloride, TDMACI) or anionic (potassium tetrakis(4-chlorophenyl)borate, KTpClPB) Lipophilic additives. PANI transforms the ionic response to an electronic signal and functions gt the same time as the membrane matrix. PANI is made soluble in dichloro methane (DCM) with the Ca2+-selective DTMBP-PO4H Ligand and membranes,can easily be prepared by drop-casting on glassy carbon (GC) substrates. PAM membranes with three different plasticizer (z) and additive (s) contents were studied (the molar ratios between the plasticizer or additive and DTMBP-PO4H are denoted as z and s, respectively). The best electrode performance, considering sensitivity and selectivity, was obtained for PANI membranes prepared with z = 0.90 and s = 0.10, containing KTpClPB as ionic additive. The Ca2+-sensitivity of this membrane was 27.8 +/- 0.2 mV/log a(Ca)(2+) (10(-1) to 10(-4) M CaCl2, LOD = 8 x 10(-7) M) in 0.1 M NaCl, and the selectivity coefficients (log K-Ca,j(pot)) towards j = Na+, K+, Li+, NH4+ and Mg2+, determined with the fixed interference method,were -3.9 +/- 0.1, -4.0 +/- 0.1, -3.5 +/- 0.1, -3.5 +/- 0.1, and -3.6 +/- 0.1, respectively. On the other hand, practically no redox or pH sensitivity was observed when TDMACI was used as the ionic additive. The PAM membranes were characterized with:potentiometry, electrochemical impedance spectroscopy (EIS) and UV-VIS.


Keywords

all-solid-state, calcium, electrically conducting polymer, ion-selective electrode, polyaniline, potentiometry, soluble

Last updated on 2019-20-10 at 02:37