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Since conjugated polymers are an important class of materials with remarkable properties in biosensor applications, in this study, a novel glucose biosensor based on a conjugated polymer was fabricated via the electropolymerization of the monomer 10,13-bis(4-hexylthiophen-2-yl)dipyridol[3,2-a:2',3'-c]phenazine onto a graphite electrode surface. Glucose oxidase (GOx) was used as the model biological recognition element. As a result of the enzymatic reaction between GOx and glucose, the glucose amount was determined by monitoring the change in the oxygen level associated with substrate concentration via the amperometric detection technique. The proposed system possessed superior properties with K-M(app) value of 0.262 mM, 2.88 x 10(-3) mM limit of detection and 105.12 mu A mM(-1) cm(-2) sensitivity. These results show that conjugated polymer film provides an effective and stable immobilization matrix for the enzyme. Finally, the biosensor was applied successfully to several commercially available beverage samples for glucose determination proving an inexpensive and highly sensitive system applicable for real time analyses. (C) 2018 Elsevier B.V. All rights reserved.

One of the bottlenecks in widespread adoption of biosensors is the large and sophisticated bioanalytical system that is required to perform signal transduction and analysis. A miniaturized bioanalytical system facilitates biosensing techniques that are portable, easy to handle and inexpensive for fast and reliable measurements of biochemical species. Thus, downscaling the bioanalytical system has become a highly active research area, significantly assisted by recent advances in the microelectronics technology. In this work, a miniaturized system is designed and implemented for amperometric detection, and subsequently tested with a glucose biosensor based on the one-step approach utilizing water soluble poly(o-aminophenol). Several experiments are conducted to assess the viability of this system including calibration, interference and application tests. The results are compared with the previously published work performed using the same biosensor tested with a commercial potentiostat in order to verify the applicability of the designed system.

In this study, amperometric biosensing performance of a novel platform utilizing a conducting polymer (CP), multi-walled carbon nanotubes (MWCNTs) and poly(amidoamine) (PAMAM) dendrimer was constructed. In order to fabricate the proposed biosensor, a graphite electrode was modified with poly[9,9-di-(2-ethylhexyl)-fluorenyl-2,7-diyl] end capped with N,N-bis(4-methylphenyl)-4-aniline (PFLA), MWCNTs and PAMAM, respectively. Then, GOx was immobilized onto the modified surface with the help of glutaraldehyde (GA) as the crosslinking reagent. Then, analytical and kinetic parameters of the constructed biosensor were investigated and the biosensor showed a linear response for glucose between 0.05 and 0.75 mM with a detection limit of 0.014 mM. KMapp and sensitivity values were calculated as 0.66 mM and 55.41 μA mM− 1 cm− 2, respectively. To investigate the surface modifications, scanning electron microscopy (SEM) and cyclic voltammetry (CV) techniques were used. Finally, fabricated biosensor was tested on beverages for glucose detection successfully.