Poly electropolymerisation

Phospholes can readily be prepared on a large scale and are known with a vast range of substituants [6, 16b,c]. However, the synthesis of oligo(phosphole)s analogous to (C) (Fig. 1) is a real synthetic challenge since the low aromatic character of phosphole prevents the functionalisation of the P-Ca,a carbon atoms via electrophilic substitution and inhibits their preparation using electropolymerisation. As a consequence, no poly(phosphole)s have yet been reported, although bi- and tetra-phospholes have been prepared by stepwise routes (Scheme 2). 

It is difficult to establish the degree of polymerisation of materials (61) due to their insolubility, which prevents GPC analysis and standard spectroscopic studies. The important bathochromic shift of the Aonset observed in the series (34a) (496 nm)/(62) (600 nm) (Scheme 18)/poly(34a) (754 nm), suggests that (61) are oligomers. Note that electropolymerisation of monomers (40a) and... 

Lobo-Castanon et al. [23] L- Lactate Cider Glutamic pyruvic transaminase (GPT) and l-lactate dehydrogenase (LDH) together with NAD+/by an electropolymerised poly-(o-phenylenediamine) (PPD) film Carbon paste modified with PPD and poly(o-aminophenol)/0 V vs. Ag/AgCl ... 

A tetraruthenated porphyrin was electropolymerised onto glassy carbon and used to catalyse the oxidation of nitrite to nitrate, with the resultant current giving a selective measure of the concentration of nitrite ion [81]. As an alternative method, soluble poly(3-octyl thiophene) [82] was cast along with tridodecylmethylammonium chloride onto glassy carbon, to give electrodes with superior selectivity over PVC-based membranes to lipophilic ions such as bromide or nitrate. 

Porphyrins are often employed in sensors on account of their ability to act as cation hosts and, with a suitable metal ion coordinated, as redox catalysts. Electropolymerised poly(metalloporphyrin)s have been used as potentiometric anion-selective electrodes [131] and as amperometric electrocatalytic sensors for many species including phenols [132], nitrous oxide [133] and oxygen [134]. Panasyuk et al. [135] have electropolymerised [nickel-(protoporphyrin IX)dimethylester] (Fig. 18.10) on glassy carbon in the presence of nitrobenzene in an attempt to prepare a nitrobenzene-selective amperometric sensor. Following extraction of the nitrobenzene the electrode was exposed to different species and cyclic voltammetric measurements made. A response was observed at the reduction potential of nitrobenzene (the polyporphyrin film acts only to accumulate the analyte and not in a catalytic fashion). Selectivity for nitrobenzene compared with w-nitroaniline and o-nitroto-luene was enhanced compared with an untreated electrode, while a glassy carbon-... 

Item 317 Synthetic Metals 59,No.2, July 1993, p.141-9 CHARACTERISATION FROM XPS, FTIR AND RAMAN SPECTROSCOPIES OF FILMS OF POLY-P-PHENYLENE PREPARED BY ELECTROPOLYMERISATION OF BENZENE DISSOLVED IN KETYL PYRIDBVIUM CHLORIDE-ALUMINnJM TRICHLORIDE MELTING SALT... 

Conducting polymers such as polypyrrole [127] and its derivatives [156,157], polyaniline [158-164], polyindole [137] and poly-o-aminobenzoic acid have recently been used for the fabrication of biosensors. A few biosensors based on insulating electropolymerised films like polyphenols, poly(o-phenylenediamine), poly(dichlorophenolindophenol) and overoxidised polypyrrole have also been elaborated [165-167]. ... 

Sundfors E, et al. Characterisation of the aluminium-electropolymerised poly (3,4-ethylenediox3fthiophene) system. J Solid State Electrochem 2010 14(7) 1185—95. 

Also an electropolymerisation process in the presence of an in-plane electrochemical potential gradient was further used to generate poly(acryhc acid) and poly(acrylamide) thickness gradients. Subsequent surface derivatisation of such thickness gradients could be used to generate peptide, lluorinated or nanoparticle gradients. 

Film devices are often developed based on polymer backbone or framework. For example, a poly-pyrrole film with borane in the backbone has been obtained by direct electropolymerisation. Boronic acid derivatised pyrroles have been employed to make molecular imprinted polymers (MIPs), for example for the detection of dopamine. Figure 8.8 shows the concept of polymer formation in the presence of analyte followed by extraction to provide highly selective pockets for dopamine to bind. The read-out in this case is based on the Fe(CN)/" redox probe. Poly-amino-boronic acid films without imprinting were employed for dopamine detection. Co-polymer sensor films based on poly(aniline-co-3-aminobenzeneboronic acid) and poly(acrylamidophenylboronic acid) have been reported. 

Very recently a differential pulse voltammetry device has been developed through imprinting smart polymers. In this experiment, which was described by N. Karimian et al, a temperature sensitive amine-terminated poly (N-isopropylacrylamide) block, and (N,N -methylenebisacryl amide) cross-linker with o-phenylenediamine were electropolymerised on the surface of a gold electrode, using folic acid as the template. This led to a thermally switchable MIP sensor with selectivity towards the template [355]. 

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