Gravimetric and viscoelastic changes during the oxidation–reduction of layer-by-layer self assembled enzyme multilayers wired by an Os-containing poly(allylamine) polymer

Surface charge effects on the redox switching of LbL self-assembled redox polyelectrolyte multilayers

“…some polycation-polyanion interaction are exchanged by the redox anion FeðCNÞ 4À 6 and the redox cation, OsðbipyÞ 3þ 3 as studied by cyclic voltammetry and electrochemical impedance spectroscopy [10]. Redox polyelectrolyte multilayers (PEM) self-assembled LbL have been reported with different redox groups attached to polymers: viologen [11][12][13][14], ferrocene [15][16][17][18][19][20][21][22], osmium bipyridyl [23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39], sulfonated polyaniline [40], polythiophene [41], cytochrome c [42], myoglobin [43], polyoxo-metalates [44], etc. Hodak et al introduced in 1997 the use of a ferrocene covalently bound to poly-(allylamine) as a molecular wire to connect electrically the enzyme glucose oxidase in a layer by layer selfassembled (LbL-SA) multilayer to generate an electrical signal in response to molecular recognition of b-D-glucose.…”

“…Hodak et al introduced in 1997 the use of a ferrocene covalently bound to poly-(allylamine) as a molecular wire to connect electrically the enzyme glucose oxidase in a layer by layer selfassembled (LbL-SA) multilayer to generate an electrical signal in response to molecular recognition of b-D-glucose. Following this first reagentless electrocatalytic active structure based on the successive alternate deposition of ferrocene modified poly(allylamine) cation and anionic glucose oxidase enzyme (GOx), an important number of authors reported similar self-contained redox mediators and enzyme strategy in amperometric biosensors [23][24][25][26][27][28][29][30][33][34][35][36][37]39,[45][46][47][48][49][50][51][52].…”

Swelling of electrochemically active polyelectrolyte multilayers

“…It was, for example, possible to determine the viscoelastic changes that accompany the swelling process by considering changes in the complex impedance load of the quartz crystal (i.e. dissipation chances) combined with the frequency changes[30,31]. A complementary tool, electrochemical ellipsometry, can be used to determine the changes in thickness and refractive index of electrochemical multilayers during swelling (seeFig.…”

Metalloporphyrin electropolymerization: electrochemical quartz crystal microgravimetric studies

“…3 summarizes the maximum ratio DR f =DX Lf in each oxidation cycle as a function of the number of oxidation cycles during NiP, CuP, CoP, ZnP and FeP film formation. With the exception of CoPP film which reaches values up to 20%, all the porphyrin films gave DR f =DX Lf ratios lower than 4%, and thus they can be treated as acoustically thin [22,23].…”