Grafted surface compounds in chemical sensors and biosensors

Лисичкин, Г. В.; Kudrinskii, A. A.

doi:10.1134/s1070363207030024

Cited by 14 publications

(13 citation statements)

References 44 publications

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“…Amine terminated chains are interesting in that they provide a template which could be further altered to enhance the selectivity of PAni. Carboxylic acid and amine groups are excellent sites for biomolecule attachment (such as proteins and saccharides) (Lisichkin and Kudrinskii, 2007;Yiu and Wright, 2005). Therefore, by functionalising PAni nanofibres, we provide a mechanism to broaden potential applications for the material.…”

Section: Discussionmentioning

confidence: 99%

Covalent attachment of functional side-groups to polyaniline nanofibres

Lahiff

Scarmagnani

Schazmann

et al. 2010

IJNM

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Polyaniline (PAni) is an example of a conducting polymer that can be switched between an insulating and a conductive state. This switching is accompanied by a colour change. Recently, interest has developed in the nanofibre form of PAni as these low dimensional structures have a very high surface area, thus enabling a faster response time. We investigate how the surface chemistry of these nanofibres can be modified by covalently attaching functional side-groups. In particular, we demonstrate the attachment of both amide and carboxylic acid groups. This can be achieved using a simple reflux technique. The modified material retains its nanomorphology and the intrinsic electrochemical, spectroscopic and redox properties of PAni are also preserved. Both acid and amine side-groups are interesting in that they provide a template, which could be further altered to enhance the selectivity of PAni. Acid terminated chains can also be used to introduce self-doping behaviour to PAni.

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Section: Discussionmentioning

confidence: 99%

Covalent attachment of functional side-groups to polyaniline nanofibres

Lahiff

Scarmagnani

Schazmann

et al. 2010

IJNM

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“…With increasing acidity, the protonated form of the radicals and the silanol groups on the surface repel each other, and, consequently, the parameter q increases. However, the point of zero charge (pzc) of the silicas surface is known to be some pH units lower than the pK a value of the silanol groups: the pzc is equal to 3.6 and 2.8 for MCM-41 and for the MPS-F127 mesoporous silicate (similar to SBA-15), respectively [38,39]. Hence, the electrostatic interaction between the negatively charged surface of the material and the positively charged radicals RH + will dominate at this pH value.…”

Section: Interpretation Of the Changes In The Parameter Q With Phmentioning

confidence: 99%

Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy

Kovaleva

Молочников

Golovkina

et al. 2013

Microporous and Mesoporous Materials

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a b s t r a c tA spin pH probe technique was used to study the influence of the channel diameter on the EPR spectra of pH-sensitive nitroxide radicals (NR) located in the channels of the mesoporous molecular sieves MCM-41 and SBA-15 with diameters ranging from 2.3 to 8.1 nm. From EPR spectra analysis and the results of the NR retention by the mesoporous molecular sieves upon washing with an aqueous KCl solution, the regularities of NR molecular location inside the channels were studied. The obtained dependence of the fraction of the radical molecules in the fast motional regime (with the rotational correlation times, s c = 2 Â 10 À11 s-9 Â 10 À11 s) in the channels of the mesoporous molecular sieves as a function of pH indicates that both NR in the fast and slow motional regime (with s c = 8 Â 10 À9

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“…Wetting of the graft copolymer surface . It is known that the wetting test is one of the most sensitive methods for controlling the quality of hydrophobic surfaces and the packing density of graft macromolecules [ 28 ]. To describe the wettability of heterogeneous surfaces containing areas of two types, the equation of A. Cassie and S. Baxter [ 29 ]:

where f 1 and f 2 are fractions, occupied by the areas with wetting angles Θ 1 and Θ 2 .…”

Section: Resultsmentioning

confidence: 99%

Mechanism of Post-Radiation-Chemical Graft Polymerization of Styrene in Polyethylene

et al. 2021

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Structural and morphological features of graft polystyrene (PS) and polyethylene (PE) copolymers produced by post-radiation chemical polymerization have been investigated by methods of X-ray microanalysis, electron microscopy, DSC and wetting angles measurement. The studied samples differed in the degree of graft, iron(II) sulphate content, sizes of PE films and distribution of graft polymer over the polyolefin cross section. It is shown that in all cases sample surfaces are enriched with PS. As the content of graft PS increases, its concentration increases both in the volume and on the surface of the samples. The distinctive feature of the post-radiation graft polymerization is the stepped curves of graft polymer distribution along the matrix cross section. A probable reason for such evolution of the distribution profiles is related to both the distribution of peroxide groups throughout the sample thickness and to the change in the monomer and iron(II) salt diffusion coefficients in the graft polyolefin layer. According to the results of electron microscope investigations and copolymer wettability during graft polymerization, a heterogeneous system is formed both in the sample volume and in the surface layer. It is shown that the melting point, glass transition temperature and degree of crystallinity of the copolymer decreases with the increasing proportion of graft PS. It is suggested that during graft polymerization a process of PE crystallite decomposition (melting) and enrichment of the amorphous phase of graft polymer by fragments of PE macromolecules occurs spontaneously. The driving force of this process is the osmotic pressure exerted by the phase network of crystallites on the growing phase of the graft PS.

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Grafted surface compounds in chemical sensors and biosensors

Cited by 14 publications

References 44 publications

Covalent attachment of functional side-groups to polyaniline nanofibres

Covalent attachment of functional side-groups to polyaniline nanofibres

Dynamics of pH-sensitive nitroxide radicals in water adsorbed in ordered mesoporous molecular sieves by EPR Spectroscopy

Mechanism of Post-Radiation-Chemical Graft Polymerization of Styrene in Polyethylene

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