Development of an Enzymeless/Mediatorless Glucose Sensor Using Ruthenium Oxide‐Prussian Blue Combinative Analogue

Abstract

Presented in this work is the first step towards an enzymeless/mediatorless glucose sensor. We first observed remarkable electrocatalytic oxidation of glucose using combinative ruthenium oxide (RuOx)-Prussian blue (PB) analogues (designated as mvRuOx-RuCN, mv: mixed valent) at ca. 1.1 V (vs. Ag/AgCl) in acidic media (pH 2 Na 2 SO 4 / H 2 SO 4 ). Individual RuOx and PB analogs failed to give any such catalytic response. A high ruthenium oxidation state (i.e., oxy/hydroxy-Ru VII , E8 % 1.4 V vs. RHE), normally occurring in strong alkaline conditions at RuOx-based electrodes, was electrogenerated and stabilized (without any conventional disproportionation reaction) in the mvRuOx-RuCN matrix for glucose catalysis. Detail X-ray photoelectron spectroscopic studies can fully support the observation. The catalyst was chemically modified onto a disposable screen-printed carbon electrode and employed for the amperometric detection of glucose via flow injection analysis (FIA). This system has a linear detection range of 0.3 -20 mM with a detection limit and sensitivity of 40 mM (S/N ¼ 3) and 6.2 mA/(mM cm 2 ), respectively, for glucose. Further steps towards the elimination of interference and the extendibility to neutral pHs were addressed.

A conductive ormosil encapsulated with ferrocene conjugate and multiwall carbon nanotubes for biosensing application

“…One linear calibration range from 0.05 to 20 mM (R ¼ 0:9974) with a sensitivity of 0.018 mA/mM was obtained. This linear range was also wider than those of 0.07-15 mM [8] and 0.3-20 mM [27] with flow injection analysis. The response time was also very fast.…”

Selective covalent immobilization of catechol on activated carbon electrodes

“…XPS and ATIR/FTIR characterization provided useful supporting information regarding the surface functionalities and topology of the activated-and CA adsorbed-carbon surfaces. Since the activation procedure is simple and selective to immobilize the CA, it is highly useful to construct a variety of electrochemical and biochemical sensors , especially using fixed potential flow-injection analysis coupled electrochemical detector, where the initial instability problems noticed with potential-cycling studies could be overcome [22]. Further work is in progress.…”

A highly sensitive enzymeless glucose sensor based on 3D graphene–Cu hybrid electrodes

“…The electro-oxidation of glucose and certain other monosaccharides were studied on various metals (Pt, Au, Pd, Cu and Ni) and their alloys (Pt-Pb, Pt-Ru, Pt-Au and Cu-Ni), and also on modified surfaces such as ruthenium dioxide, cobalt oxide (Co 3 O 4 ) and nickel oxide. [16][17][18][19] In a previous report, it was shown that the size of Ni (OH) 2 nanoparticles (NPs) played a vital role on their electrocatalytic activity toward glucose oxidation. However, the electrocatalytic activity not only depends on size, morphology, surface texture, and crystalline structure of nanomaterials, but also on the nature of the support.…”