Redox-active self-assembled monolayers as novel solid contacts for ion-selective electrodes

Fibbioli, Monia; Bandyopadhyay, K.; Liu, Sheng Gao; Echegoyen, Luís; Enger, Olivier; Diederich, François; Bühlmann, Philippe; Pretsch, Ernö

doi:10.1039/a909532b

Cited by 124 publications

(118 citation statements)

References 23 publications

Supporting

Mentioning

114

Contrasting

Unclassified

Order By: Relevance

“…It was recently shown that water-layer tests are also negative with PPy that had been electropolymerized in the presence of potassium hexacyanoferrate(II)/(III) [39]. This was the first time that no water layer had been observed with PVC membranes of conventional composition, because previously the absence of a water film had only been observed with SAM-or CP-based SC-ISE, either with other polymers [20,21,38] or with membranes containing less than the usual amount of plasticizer [20,21]. In this paper, we show for the first time that it is possible to achieve nanomolar detection limits with conventional plasticized PVC membranes using CP-based SC-ISE.…”

Section: Introductionmentioning

confidence: 89%

“…Their potential instability was attributed to lack of control of the concentrations of the species defining the redox potential at the membrane/metal interface [12,16,17] and their response characteristics were successfully improved by adding an appropriate redox-active component to the PVC membrane [18] or by using an intermediate redox-active polymer layer [19]. Similarly, the presence of a redox-active self-assembled monolayer (SAM) between the polymeric membrane and the inner Au electrode also leads to very stable systems [20,21]. In numerous contributions, the metal surface has been covered by conducting polymers (CP) such as polypyrrole (PPy) [22][23][24][25], polyaniline [26], poly(3-octylthiophene) (POT) [27][28][29], and poly(3,4-ethylenedioxythiophene) [30,31].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A polypyrrole-based solid-contact Pb2+-selective PVC-membrane electrode with a nanomolar detection limit

et al. 2004

View full text Add to dashboard Cite

Ion-selective electrodes (ISE) based on conventional plasticized PVC membranes with solid inner contact (SC) have so far had unsatisfactory lower detection limits. Here it is shown that electropolymerization of pyrrole in the presence of potassium hexacyanoferrate(II)/(III) on Pt results in adequate inner contact for SC-ISE. The nanomolar lower detection limit achieved with the Pb 2+ -selective PVC membranes investigated is comparable with values obtained with optimized internal solutions of liquid-contact ISE.

show abstract

Section: Introductionmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

A polypyrrole-based solid-contact Pb2+-selective PVC-membrane electrode with a nanomolar detection limit

et al. 2004

View full text Add to dashboard Cite

show abstract

“…The corresponding crown-annelated TTF bis-alcohol precursors were prepared in reasonable yields following a modification of the literature procedures (28,29,46). The mono-alcohol precursors to synthesize 2a and 2b were obtained by controlled reduction of the ester group of diester EDT-TTF (47).…”

Section: Resultsmentioning

confidence: 99%

Metal ion recognition and molecular templating in self-assembled monolayers of cyclic and acyclic polyethers

Herranz

Colonna

Echegoyen

2002

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Our recent work with cyclic and acyclic polyether self-assembled monolayers (SAMs) on gold is presented. A series of dithia-crowntetrathiafulvalene derivatives with one or two disulfide groups has been prepared, and their SAMs on gold have been characterized by electrochemistry and by reflection-absorption infrared spectroscopy. These SAMs are extremely stable on repeated electrochemical potential scans and can selectively recognize alkali metal ions. Acyclic polyether derivatives can also self-assemble on gold to yield selective metal ion recognition domains. Impedance spectroscopy data for these SAMs fit the Langmuir isotherm and allow the determination of ion association constants. Some of the SAMs prepared with new acyclic polyether derivatives are able to detect potassium cations selectively when templated in their presence. These structures are believed to be a consequence of ion ''imprinting'' during the process of SAM formation.T he easy preparation, stability, and versatility of self-assembled monolayers (SAMs) has resulted in considerable activity in this field since the first publication by Nuzzo and Allara (1). Molecular recognition is especially relevant on surfaces because it allows the control of the exchange of signals, structures, and energy through the interfaces (2-4). SAMs allow the introduction of functional groups in the adsorbates, thus offering a powerful way to develop systems that have applications as sensors, devices, and switches (5). Some recent articles have reported surface structures with hydrophobic and hydrophilic properties arranged in nano-strips and honeycomb or homogeneous structures (6), whereas others have detected photo and electrochemical conversion of cis to trans forms within the SAM (7). Other examples have shown the formation of chiral imprinted sites (8). SAM structures have also been prepared for the recognition and sensing of metal ions (9), some of which are electrochemically active (10-18).Relatively recently, and Bryce et al. (23,24) reported, almost simultaneously, the incorporation of crownether groups into SAMs and their use as potential metal ion sensors. The Reinhoudt group used electrochemical impedance spectroscopy (EIS) for SAM characterization and to study the ion recognition processes (19)(20)(21)(22). This technique enables the detection of interfacial ion recognition phenomena when both guest ion and host monolayer are electrochemically inactive, by detecting changes of the charge-transfer resistance induced by metal ion binding (see Fig. 1a; refs. 25 and 26). The report by Bryce et al. (23,24) described SAMs of crown-annelated tetrathiafulvalene (TTF) derivatives, which showed, by cyclic voltammetry (CV), a redox potential shift of the electroactive, surface-confined, crown-TTF group on ion complexation (23, 24). The first TTF-crown SAMs reported by this group were apparently unstable after several electrochemical scans (23). However, in a subsequent report they demonstrated that the stability and electrochemical behavior of the SAMs can be improv...

show abstract

“…[18][19][20][21] The role of the SC is to provide a stable inner phase boundary potential 20,22,23 at the substrate/SC and SC/ISM interfaces, and to prevent the aqueous layer formation at the inner interface, which coupled to diffusion of ionic species within the ISM may lead to potential instability. 24 As all ISMs exhibit water uptake [25][26][27][28][29][30][31] , the prevention of the aqueous layer formation 32,33 with ill-defined ion activity has proven to be a major challenge.…”

mentioning

confidence: 99%

“…The mainstream of the SCISE research is based on electrically conducting polymers (ECPs) [34][35][36] , large surface area carbon materials 32,[37][38][39][40] and their (nano)composites [41][42][43] , but also many other important types of SC materials have been reported such as redox polymers 44 , electronion exchange resins 45 , redox-active self-assembled monolayers 32 , tetrakis(4-chlorophenyl)borate anion doped nanocluster films 46 , nanoporous Au films 47 , and threedimensional molybdenum sulfide nanoflowers. 48 SCISEs with adequate potential stability were reported for both the ECP and carbon materials, but the use of large surface area inert carbon materials apparently results in better potential stabilities and less susceptibility to environmental conditions.…”

mentioning

confidence: 99%

Pre-Polarized Hydrophobic Conducting Polymer Solid-Contact Ion-Selective Electrodes with Improved Potential Reproducibility

Papp

Lindfors

et al. 2017

Anal. Chem.

View full text Add to dashboard Cite

Electrically conducting polymers (ECPs) are one of the most popular types of materials to interface ion-selective membranes (ISMs) with electron conducting substrates to construct solid contact ion-selective electrodes (SCISEs). For optimal ion-to-electron transduction and potential stability, the p-doped ECPs with low oxidation potentials such as PPy need to be generally in their conducting form along with providing a sufficiently hydrophobic interface to counteract the aqueous layer formation. The first criterion requires that the ECPs are in their oxidized state, but the high charge density of this state is detrimental for the prevention of the aqueous layer formation. We offer here a solution to this paradox by implementing a highly hydrophobic perfluorinated anion (perfluorooctane sulfonate, PFOS -) as doping ion by 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 which the oxidized form of the ECP becomes hydrophobic. The proof of concept is shown by using polypyrrole (PPy) films doped with PFOS -(PPy-PFOS) as the solid contact in K + -selective SCISEs (K + -SCISE). Prior to applying the plasticized poly(vinyl chloride) ISM, the oxidation state of the electrodeposited PPy-PFOS was adjusted by polarization to the known open circuit potential of the solid contact in 0.1 M KCl. We show that the pre-polarization results in a hydrophobic PPy-PFOS film with a water contact angle of 97±5º, which effectively prevents the aqueous layer formation under the ISM. Under optimal conditions the K + -SCISEs had a very low standard deviation of E 0 of only 501.0±0.7 mV that is the best E 0 reproducibility reported for ECP-based SCISEs.

show abstract

Redox-active self-assembled monolayers as novel solid contacts for ion-selective electrodes

Cited by 124 publications

References 23 publications

A polypyrrole-based solid-contact Pb2+-selective PVC-membrane electrode with a nanomolar detection limit

A polypyrrole-based solid-contact Pb2+-selective PVC-membrane electrode with a nanomolar detection limit

Metal ion recognition and molecular templating in self-assembled monolayers of cyclic and acyclic polyethers

Pre-Polarized Hydrophobic Conducting Polymer Solid-Contact Ion-Selective Electrodes with Improved Potential Reproducibility

Contact Info

Product

Resources

About