A Glucose Biosensor Employing a Stable Artificial Peroxidase Based on Ruthenium Purple Anchored Cinder

Abstract

Iron-enriched industrial waste cinder (CFe*) has been recycled for efficient and stable anchoring of Ru(CN)6(4-) to the formation of a hybrid ruthenium purple complex. The cinder/ruthenium purple hybrid-modified carbon paste electrode (designated as CPE/CFe*-RP) was worked out for hydrodynamic analysis of H2O2 at a low detecting potential of 0.0 V versus Ag/AgCl in pH 7 ammonium buffer solution. The highly active, selective, and stable electrocatalytic system with a function similar to peroxidase enzyme shows a linear calibration curve up to 0.8 mM H2O2 at a rotation rate of 3600 rpm with slope and detection limit (S/N = 3) of 0.11 microA/microM and 33 nM, respectively. Interference by direct electrochemical oxidation of easily oxidizable substances can be prevented as a result of the low detecting potential of the working system. A glucose biosensor was further constructed by coating with glucose oxidase and Tosflex on the CPE/CFe*-RP (denoted as CPE/CFe*-RP/GOx/Ts). The proposed CPE/CFe*-RP/GOx/Ts with a two-layer configuration, that is, enzyme and protecting layers, exhibits good operational performance in terms of response time, linearity, detection limit, and lifetime.

Novel Electrochemical Microsensor for Hydrogen Peroxide based on Iron‐Ruthenium Hexacyanoferrate Modified Carbon Fiber Electrode

“…This is in contrast with our observations at neutral pH, where spectrophotometric analysis of the mixed-metal deposition solution revealed an absorption maximum at 670 nm, in comparison with 420 nm and 500 nm for the FeHCF and RuHCF modification solutions, respectively, indicating that the mixed-metal complex already exists in the modification solution. It is assumed that under the experimental conditions employed in this work, the simultaneous deposition of both cations and [Fe(CN) 6 ] 3À from the same solution precluded the formation of ruthenium-oxo species, which were found in several ruthenium-stabilized metal hexacyanoferrate films [33]. However, similar to observations described by Cataldis group [21,32,33], the ruthenium containing mixed-metal hexacyanoferrate film in our study exhibited increased stability when compared with mono-cationic FeHCF or RuHCF analogues.…”

“…The current increase is attributed to changes in the FeRuHCF film structure, possibly together with an increase in the film lattice spaces allowing H 2 O 2 to penetrate more easily into the film. However, reduction of Fe(CN) 6 3À to Fe(CN) 6…”

“…However, the mixed FeRuHCF film was composed of small crystals which covered the entire electrode surface, although different thicknesses of the film were observed while prepared under identical conditions. Cataldi et al describe the formation of an oxo-bridge between ruthenium cation and cyano group deposited from an acidic solution containing RuCl 3 and K 3 Fe(CN) 6 in the molar ratio of 1 : 1 [32]. This is in contrast with our observations at neutral pH, where spectrophotometric analysis of the mixed-metal deposition solution revealed an absorption maximum at 670 nm, in comparison with 420 nm and 500 nm for the FeHCF and RuHCF modification solutions, respectively, indicating that the mixed-metal complex already exists in the modification solution.…”

“…It is also a by-product of many biological oxidative reactions, e.g., glucose oxidase/glucose [5] and other oxidases, and is therefore an important parameter for monitoring biological processes. In particular, when meeting high demands addressing strict diabetes control, substantial research efforts have been focused toward development of reliable glucose sensors based on the electrochemical detection of hydrogen peroxide, which is formed during enzyme-catalyzed oxidation of glucose by dissolved oxygen [6,7]. Various, and particularly biomedical applications such as continuous in-vivo monitoring of hydrogen peroxide (and hence glucose) with, for example, implantable or needle-like sensors [8,9] and measurements in different microenvironments, e.g., plant cells [10], dictate the miniaturization of electrochemical sensors down to micro and submicrometer design.…”

Functionalised ZnO-nanorod-based selective electrochemical sensor for intracellular glucose

“…When glucose levels in the bloodstream are not properly regulated, diseases such as diabetes can develop. Because of the high demand for blood-glucose monitoring, significant research has been devoted to producing reliable methods for in vitro or in vivo glucose measurement, such as fluorescence spectroscopy (Ballerstadt and Schultz, 2000), diffraction spectroscopy (Asher et al, 2003), surface-enhanced Raman scattering (Shafer et al, 2003), a wireless magnetoelastic sensor (Cai et al, 2004), an electrochemical transistor sensor (Forzani et al, 2004;Raffa et al, 2003), an enzyme-based amperometric sensor (Zen et al, 2003;Hrapovic et al, 2004;Lin et al, 2004;Yang et al, 2004;Zhou et al, 2005), a nanoenzymetric amperometric sensor (Park et al, 2003), nuclear magnetic resonance spectroscopy (Cline et al, 1998) and a potentiometric sensor (Shoji et al, 2001). Since the development of the first glucose biosensor, improvement of the response performance of enzyme electrodes has been the main focus of biosensor research (Raitman et al, 2002).…”