Thin film bienzyme amperometric biosensors based on polymeric redox mediators with electrostatic bipolar protecting layer

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

“…This valué of ^ivi.app obtained is larger than the intrinsic valué and the linearly measurable range is greatly enhanced. In fact, it has been reported previously that the linear range of glucose sensors can be increased substantially by using an additional polymer coating on the surface of the sensor [52,53]. In the same way, the copolymer probably provides an intrinsic resistance to the diffusion of glucose, due to the compact structure of the films.…”

The synergetIc effect of redox mediators and peroxidase in a bienzymatic biosensor for glucose assays in FIA

“…The recorded current will then be proportional to the glucose concentration in the sample. Previously it has been clearly shown that using polymeric bound mediators and especially polymeric mediators covalently bound with the enzyme is beneficial to obtain stable biosensors [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60]. However, in the case stipulated in this work when coimmobilising GOD and HRP it has been possible to achieve long term stable sensors.…”

“…The use of mediators is a well-known technique although the way of adding the mediator to the bienzymatic system (oxidase/peroxidase) may vary. A number of different mediators have been used as additions into sample solutions such as, potassium hexacyanoferrate (II) [18][19][20][21][22][23][24] [44,45], and Nafion-Nmethyl phenazinium [46]. The advantages of using the redox polymers are several, but mainly they result in more stable biosensors since leaking of the mediator from the electrode is minimised and higher and faster responses are observed due to the proximity between the enzyme and the mediator.…”

“…Bienzymatic biosensors have also been developed with deposition of mediators such as hydroxymethyl ferrocene [30], 1,1'-dimethyl ferrocene [31], tetracyanoquinodimethane (TCNQ) [32], and 3,3',5,5'-tetramethylbenzidine [33] on the surface or inside the electrode. Moreover, different redox polymers have been used as mediators including osmium polymers [34][35][36][37][38][39][40][41], polypyrrole [42,43], ferrocene polymers [44,45], and Nafion-Nmethyl phenazinium [46]. The advantages of using the redox polymers are several, but mainly they result in more stable biosensors since leaking of the mediator from the electrode is minimised and higher and faster responses are observed due to the proximity between the enzyme and the mediator.…”

Amperometric Glucose Sensors for Whole Blood Measurement Based on Dehydrogenase Enzymes

“…An attractive approach to tackle this challenge is to use a polymeric mediator which has mediator moieties chemically attached to polymer chains. Because of its large molecular size, the polymeric mediator can be co-immobilized with enzyme at electrode by various means, including surface grafting, [31][32][33][34] layer-by-layer surface adsorption, [35][36][37] retention behind semi-permeable dialysis membranes, [38][39][40] physical entrapment [41][42][43] or cross-link in hydrogels, [44][45][46][47] entrapment in electropolymerized [48,49] or chemically formed layers [50] or in inorganic layers, [51,52] and blend in carbon pastes. [53] At LifeScan Scotland Limited, we have synthesized a ferrocene polymeric mediator which is a copolymer of vinylferrocene, acrylamide and 2-(diethylamino)ethyl methacrylate.…”