Electrochemical and bioelectrocatalytical properties of novel block-copolymers containing interacting ferrocenyl units

Abstract

The electrochemical characterization of three different polystyrene-b-polybutadiene block-copolymers, functionalized with diferrocenylsilane units, is reported. The PB-blocks have been functionalized with different fractions of electronically communicated, PS m -PB" p (HSiMeFc 2 ) p units, where m = 615, n = 53, p = 39 (1), m = 375, n = 92, p = 76 (2) and m = 455, n = 204, p = 170 (3). Electrochemical characterization has been carried out both in solution and after electrochemical deposition onto platinum electrodes. The bioelectrocatalytical properties of electrodes modified with the polymers in the nicotinamide dinucleotide (NADH) and glucose oxidase (GOx) oxidations have been investigated as a function of the constitution and structure of the polymers. The analytical properties of electrodes modified with these polymers as sensors of NADH and GOx are described. In addition, an amperometric biosensor for glucose, prepared by electrostatic immobilization of glucose oxidase onto a platinum electrode modified with one of the ferrocenyl block-copolymers as an example, has been developed.

Multioperational Oxidase Biosensors Based on Carbosilane Dendrimers with Interacting Ferrocenes

“…The values of K app ' calculated for biosensors built with Dend1 and Dend2 were 36.8 and 69.4 nA mM À1 respectively. A similar kinetic behaviour was found for enzyme electrodes prepared with polyhedral siloxane polymers [7] and block copolymers [33] with the same immobilization procedure.…”

Porous Carbons – Hyperbranched Polymers – Polymer Solvation

“…Due to missing entanglements, no free-standing films could be prepared from the F-hb-PAEPO and no mechanical properties could be recorded. An interesting finding was observed from 19 F-NMR spectra that indicated partial loss of 4-fluoro groups from unreacted B sites, as also observed previously by Fossum and coworkers [167] but was not explained. This effect was also manifested on the DB of the F-hb-PAEPO, which was approximated to 53 or 59% using the equations given by Frechét or Frey, respectively, but the DB should be~50% without unwanted side reactions.…”

“…Bernal et al [167] further extended their work and prepared hb-PAEPOs with controlled molecular weights and narrow Ð by the polymerization of bis-(4-fluorophenyl)-(4-hydroxyphenyl)phosphine oxide in the presence of three core molecules. Polymerization reactions of bis-(4-fluorophenyl)-(4-hydroxyphenyl)phosphine oxide (1-26, Scheme 10) in the presence of 3, 5, and 10 mol% of tris(4-fluorophenyl)phosphine oxide (1-30, Scheme 10), tris (3,4-difluorophenyl)phosphine oxide (1-31, Scheme 10), and tris(3,4,5trifluorophenyl)phosphine oxide (1-32, Scheme 10), respectively, were carried out in NMP at reflux in the presence of K 2 CO 3 , with reaction times of 8 h. The more reactive the core toward nucleophilic aromatic substitution, the more control was provided over the final molecular weight and the resultant Ð. Polymers showed M n values ranging from 3,270 to 8,100 Da for polymerization reactions in the presence of core molecules.…”

“…In this case, even diblock copolymers precipitate on the electrode, without indication of the formation of micellar structures upon electrochemical switching [166][167][168]. Co-precipitation with carbon nanotubes onto electrodes has been achieved [169].…”

Electrochemical Study of Anionic Ferrocene Derivatives Intercalated in Layered Double Hydroxides: Application to Glucose Amperometric Biosensors

“…A number of cases has been reported where glucose oxidase and ferrocene derivatives both are immobilized at the electrode surface leading to heterogeneous electron transfer. Besides conducting polymers with grafted ferrocene units [24], various inorganic materials, such as ormosil [25], sono-gel [26], titanium oxide [27], and vanadium pentoxide xerogel [28] have also been used as immobilization matrices for the fabrication of mediated glucose biosensors.…”