Use of substrate coated electrodes and AC impedance spectroscopy for the detection of enzyme activity

Saum, A.G.E; Cumming, R. H.; Rowell, Frederick J.

doi:10.1016/s0956-5663(97)00129-2

Cited by 68 publications

(34 citation statements)

References 11 publications

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“…Alternatively the biocatalytic process could result in the degradation and dissolution of a polymer film or membrane associated with the electrode surface [168,169]. The former process will result in the insulation of the conductive surface and, thus, the electron transfer resistance will increase, whereas the latter process will result in the enhanced penetration of a redox probe through the membrane, and, therefore, the electron transfer resistance will decrease.…”

Section: Impedimetric Sensing Of Electron Transfer Barriersmentioning

confidence: 99%

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

2003

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Impedance spectroscopy is a rapidly developing electrochemical technique for the characterization of biomaterialfunctionalized electrodes and biocatalytic transformations at electrode surfaces, and specifically for the transduction of biosensing events at electrodes or field-effect transistor devices. The immobilization of biomaterials, e.g., enzymes, antigens/antibodies or DNA on electrodes or semiconductor surfaces alters the capacitance and interfacial electron transfer resistance of the conductive or semiconductive electrodes. Impedance spectroscopy allows analysis of interfacial changes originating from biorecognition events at electrode surfaces. Kinetics and mechanisms of electron transfer processes corresponding to biocatalytic reactions occurring at modified electrodes can be also derived from Faradaic impedance spectroscopy. Different immunosensors that use impedance measurements for the transduction of antigen-antibody complex formation on electronic transducers were developed. Similarly, DNA biosensors using impedance measurements as readout signals were developed. Amplified detection of the analyte DNA using Faradaic impedance spectroscopy was accomplished by the coupling of functionalized liposomes or by the association of biocatalytic conjugates to the sensing interface providing biocatalyzed precipitation of an insoluble product on the electrodes. The amplified detections of viral DNA and single-base mismatches in DNA were accomplished by similar methods. The changes of interfacial features of gate surfaces of field-effect transistors (FET) upon the formation of antigen-antibody complexes or assembly of protein arrays were probed by impedance measurements and specifically by transconductance measurements. Impedance spectroscopy was also applied to characterize enzymebased biosensors. The reconstitution of apo-enzymes on cofactor-functionalized electrodes and the formation of cofactor-enzyme affinity complexes on electrodes were probed by Faradaic impedance spectroscopy. Also biocatalyzed reactions occurring on electrode surfaces were analyzed by impedance spectroscopy. The theoretical background of the different methods and their practical applications in analytical procedures were outlined in this article.

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Section: Impedimetric Sensing Of Electron Transfer Barriersmentioning

confidence: 99%

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

2003

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“…For example, Saum et al monitored collagenase activity by depositing its natural substrate gelatin onto interdigitated electrodes. 19 Collagenase concentrations as low as 0.2 mg ml À1 were detected; however, only low electrolyte concentrations could be used for reliable impedance measurements due to the hydrophilic nature of the films. Millington et al detected trypsin using holograms based on gelatin.…”

Section: Protease Sensors Based On the Degradation Of Thin Filmsmentioning

confidence: 99%

Generic protease detection technology for monitoring periodontal disease

et al. 2011

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Periodontal diseases are inflammatory conditions that affect the supporting tissues of teeth and can lead to destruction of the bone support and ultimately tooth loss if untreated. Progression of periodontitis is usually site specific but not uniform, and currently there are no accurate clinical methods for distinguishing sites where there is active disease progression from sites that are quiescent. Consequently, unnecessary and costly treatment of periodontal sites that are not progressing may occur. Three proteases have been identified as suitable markers for distinguishing sites with active disease progression and quiescent sites: human neutrophil elastase, cathepsin G and MMP8. Generic sensor materials for the detection of these three proteases have been developed based on thin dextran hydrogel films cross-linked with peptides. Degradation of the hydrogel films was monitored using impedance measurements. The target proteases were detected in the clinically relevant range within a time frame of 3 min. Good specificity for different proteases was achieved by choosing appropriate peptide cross-linkers.

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“…In both faradaic and nonfaradaic processes, impedance changes may be quantified through C dl as shown in Equation 2. Changes in film thickness as a result of biocomplex formation [19,24] where A is the electrode area, d is the monolayer thickness, e is the dielectric constant and e o is the permittivity of free space. C dl is a combination of the capacitance of the bare electrode (C elec ) and that contributed by the adsorbed biological membrane (C mem ).…”

Section: General Principlesmentioning

confidence: 99%

Impedance Spectroscopy: A Powerful Tool for Rapid Biomolecular Screening and Cell Culture Monitoring

2005

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Dielectric spectroscopy or Electrochemical impedance spectroscopy (EIS) is traditionally used in corrosion monitoring, coatings evaluation, batteries, and electrodeposition and semiconductor characterization. However, in recent years, it is gaining widespread application in biotechnology, tissue engineering, and characterization of biological cells, disease diagnosis and cell culture monitoring. This article discusses the principles and implementation of dielectric spectroscopy in these bioanalytical applications. It provides examples of EIS as label-free, mediator-free strategies for rapid screening of biocompatible surfaces, monitoring pathogenic bacteria, as well as the analysis of heterogeneous systems, especially biological cells and tissues. Descriptions are given of the application of nanoparticles to improve the analytical sensitivities in EIS. Specific examples are given of the detection of base pair mismatches in the DNA sequence of Hepatitis B disease, TaySachs disease and Microcystis spp. Others include the EIS detection of viable pathogenic bacteria and the influence of nanomaterials in enhancing biosensor performance. Expanding applications in tissue engineering such as adsorption of proteins onto thiolated hexa(-ethylene glycol)-terminated (EG6) self-assembled monolayer (SAM) are discussed.

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Use of substrate coated electrodes and AC impedance spectroscopy for the detection of enzyme activity

Cited by 68 publications

References 11 publications

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

Probing Biomolecular Interactions at Conductive and Semiconductive Surfaces by Impedance Spectroscopy: Routes to Impedimetric Immunosensors, DNA‐Sensors, and Enzyme Biosensors

Generic protease detection technology for monitoring periodontal disease

Impedance Spectroscopy: A Powerful Tool for Rapid Biomolecular Screening and Cell Culture Monitoring

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