Glucose Biosensors Based on Electrodes Modified with Ferrocene Derivatives Intercalated into Mg/Al Layered Double Hydroxides (original) (raw)
Related papers
Journal of the Brazilian Chemical Society, 2001
Neste trabalho é apresentada a co-imobilização de GOx e ferroceno numa matriz polimérica através de um método simples de uma etapa. Esse procedimento para a imobilização de ferroceno como mediador da reação enzimática não envolve a modificação do monômero ou da enzima, o que poderia levar à perda de sua atividade. A incorporação de ferroceno se traduz no incremento da sensibilidade, comparado ao sensor sem mediador redox (1,5 vs 0,23 µA mmol-1 L cm-2) e diminuição do potencial de trabalho até 0,4 V. O sensor desenvolvido mostra resposta linear até 10 mmol L-1 e um tempo de resposta de 2 s, além de razoável estabilidade depois de uma semana de uso. The co-immobilization of GOx and ferrocene in a polymeric matrix by a one-step simple method is presented. This procedure to immobilize ferrocene as mediator implies the absence of modification of the monomer or the enzyme that would lead to the loss of its activity. Ferrocene incorporation results in an increase of sensitivity compared with the sensor prepared without the redox mediator (1.5 vs 0.23 µA mmol-1 L cm-2) and the decrease of the working potential to 0.4 V. The prepared sensor shows linear response till 10 mmol L-1 and response time of 2 s, in addition to reasonable stability after one week.
This work reports on a new amperometric glucose biosensor based on the modification of glassy carbon and screen printed electrodes with rhodium as catalyst, glucose oxidase (GOx) as biorecognition element, and in situ electrogenerated polytyramine as anti-interferents barrier. The excellent electrocatalytic activity of rhodium makes possible a huge enhancement in the oxidation currents of the hydrogen peroxide enzymatically generated from glucose. The polytyramine layer largely improves the selectivity of such response. No interference is observed even for large excess of ascorbic acid, uric acid and acetaminophen. A fast response (5 s) is obtained at the glassy carbon electrode modified with rhodium, glucose oxidase and polytyramine, with a linear relationship between current and glucose concentration up to 1.50 × 10 −2 M (2.70 g/L) and a the detection limit of 2.5 × 10 −5 M (0.0045 g/L). In the case of screen printed-modified electrodes the response is linear up to 1.0 × 10 −2 M (1.80 g/L) glucose. The effect of the experimental conditions for the preparation of the biosensor on the analytical performance of the resulting bioelectrodes is examined and optimized.
Biosensors and Bioelectronics, 2003
The electrochemical performance of a new glucose biosensor is reported. The glucose biosensor is developed using glucose oxidase (GOD) and ferrocene encapsulated palladium (Pd)-linked organically modified sol Á/gel glass (ORMOSIL) material incorporated within graphite paste electrode. The ORMOSIL material incorporated within graphite paste electrode behaves as an excellent electrocatalyst for the oxidation of enzymatically reduced GOD. The electrochemical behavior of new glucose biosensor has been examined by cyclic volammetry and amperometric measurements. The bioelectrocatalysis of ORMOSIL embedded within graphite paste as a function of storage time and varying concentration of ORMOSIL is reported. The initial amperometric response on glucose sensing is recorded to be 145 mA at 15% (w/w) concentration of the ORMOSIL which is decreased to 20 mA at 5% of the same keeping GOD concentration constant. The variation of electrochemical behavior of the ORMOSIL embedded within graphite paste as a function of time has also been studied based on cyclic voltammetry. The voltammograms showing the reversible electrochemistry of ORMOSIL encapsulated ferrocene is changed into a plateau shape as a function of time, however, the electrocatalytic behavior is still retained. The practical usability of new glucose sensor has been compared with earlier developed glucose sensor. The sensitivity, response time and linearity of the new glucose biosensor are found to be excellent over earlier reported glucose biosensor. The amperometric response, calibration curve and practical applications of new glucose sensor are reported.
Electroanalysis, 1996
The voltammograms obtained with an electrode containing carbon paste with ferrocene immobilized on a titanium-oxide/silica gel material showed good response and stability in aqueous media. From pH 4 to 8 the electrode response remained almost constant, but a small shift in the midpoint potential towards more positive values was observed when the pH was decreased. The nature of the cation does not affect the voltammetric response. However, the nature of the anion affects the midpoint potential significantly. Cyclic voltammetry investigation showed that the electrode with immobilized glucose oxidase is an excellent biosensor. The mechanism of the electron transfer was proposed as being electron tunneling by the flavin of the enzyme to mediator, and the high current level is assigned to the high surface area of the silica matrix. The amperometric measurements showed a linear response in the range from 1.0 x M. Above this range, saturation of the enzyme was observed. The response time was about 15 s. Determination of glucose in blood serum showed an excellent correlation when compared with Merck's Kit method. The immobilized material presented an excellent stability mantaining the same activity for at least six months.
Current advancements and prospects of enzymatic and non-enzymatic electrochemical glucose sensors
International Journal of Biological Macromolecules, 2023
This review discusses the most current developments and future perspectives in enzymatic and non-enzymatic glucose sensors, which have notably evolved over the preceding quadrennial period. Furthermore, a thorough exploration encompassed the sensor's intricate fabrication processes, the diverse range of materials employed, the underlying principles of detection, and an in-depth assessment of the sensors' efficacy in detecting glucose levels within essential bodily fluids such as human blood serums, urine, saliva, and interstitial fluids. It is worth noting that the accurate quantification of glucose concentrations within human blood has been effectively achieved by utilizing classical enzymatic sensors harmoniously integrated with optical and electrochemical transduction mechanisms. Monitoring glucose levels in various mediums has attracted exceptional attention from industrial to academic researchers for diabetes management, food quality control, clinical medicine, and bioprocess inspection. There has been an enormous demand for the creation of novel glucose sensors over the past ten years. Research has primarily concentrated on succeeding biocompatible and enhanced sensing abilities related to the present technologies, offering innovative avenues for more effective glucose sensors. Recent developments in wearable optical and electrochemical sensors with low cost, high stability, point-of-care testing, and online tracking of glucose concentration levels in biological fluids can aid in managing and controlling diabetes globally. New nanomaterials and biomolecules that can be used in electrochemical sensor systems to identify glucose concentration levels are developed thanks to advances in nanoscience and nanotechnology. Both enzymatic and non-enzymatic glucose electrochemical sensors have garnered much interest recently and have made significant strides in detecting glucose levels. In this review, we summarise several categories of non-enzymatic glucose sensor materials, including composites, non-precious transition metals and their metal oxides, hydroxides, precious metals and their alloys, carbon-based materials, conducting polymers, metal-organic framework (MOF)-based electrocatalysts, and wearable device-based glucose sensors deeply.
Bioelectrochemistry, 2014
Multi-wall carbon nanotubes (MWNTs) functionalized with amino groups were prepared via silane treatment using 3-aminopropyltrimethoxysilane (APS) as a silane-coupling agent. The resultant amino terminated MWNTs (AMWNTs) were applied to construct glucose biosensors with IO 4 −-oxidized glucose oxidase (IO 4 −-oxidized GOx) through the layer-by-layer (LBL) covalent self-assembly method without any cross-linker. Scanning electron microscopy (SEM) indicated that the assembled AMWNTs were almost in a form of small bundles or single nanotubes, and the surface density increased uniformly with the number of GOx/AMWNTs bilayers. From the analysis of voltammetric signals, a linear increment of the coverage of GOx per bilayer was estimated. The resulting biosensor showed excellent catalytic activity towards the electroreduction of dissolved oxygen at low overvoltage, based on which glucose concentration was monitored conveniently. The enzyme electrode exhibited good electrocatalytic response towards the glucose and that response increased with the number of GOx/AMWNTs bilayers, suggesting that the analytical performance such as sensitivity and detection limit of the glucose biosensors could be tuned to the desired level by adjusting the number of deposited GOx/AMWNTs bilayers. The biosensor constructed with four bilayers of GOx/AMWNTs showed high sensitivity of 7.46 A mM −1 cm −2 and the detection limit of 8.0 M, with a fast response less than 10 s. Because of relative low applied potential, the interference from other electro-oxidizable compounds was minimized, which improved the selectivity of the biosensors. Furthermore, the obtained enzyme electrodes also showed remarkable stability due to the covalent interaction between the GOx and AMWNTs.
Continuous glucose microsensor with a nanoscale conducting matrix and redox mediator
Electrochimica Acta, 2012
A glucose microsensor with a nanoscale conducting matrix and redox mediator has been developed and results of a detailed in vitro and ex vivo study of glucose consumption are presented. This microsensor is a conducting polymeric glucose monitoring device and is based on an enzymatic detection technique. A multilayer multipolymeric fabrication approach using biocompatible materials was investigated to construct such a microsensor device. A novel two-electrode electrochemical sensing cell consisting of a modified platinum working electrode (WE) with selective deposition of a conducting polymer polypyrrole (PPy) and a plain platinum (pseudo-reference/counter) electrode has been used. As a redox mediator, the ferrocene molecule has been successfully immobilized in the nanoscale PPy matrix that is deposited onto the surface of the WE. The ferrocene redox mediator lowers the operational potential of the sensor and helps avoid the introduction of noise and oxidation of interference molecules such as ascorbic acid and uric acid. Good sensitivity (∼20 nA/mM of glucose) and selectivity for glucose were accomplished. Detailed structural, in vitro and ex vivo properties as well as calibration results of the microsensor device are presented.
Review on Recent Developments in Non-Enzymatic Electrochemical Glucose Sensors
Currently, there is a great demand for the development and improvement of glucose sensors for significance in biomedical applications. Special attention is given to the discussion on some problems and bottlenecks in areas of non-enzymatic and enzymatic (glucose oxidase based) amperometric glucose sensing. The evolution of first to third generation electrochemical glucose sensors reflects a simplification and enhancement of the transduction pathway. In order to meet special needs, a move towards non-enzymatic glucose sensors has begun. These new sensors have garnered significant interest due to their capacity to achieve continuous glucose monitoring, their high stability compared to traditional glucose sensors, and the ease of their fabrication. Research has been extensively geared towards the preparation of these non-enzymatic glucose sensors from novel materials, often with nanostructures, which possess ideal properties for electrochemical sensor applications. In the recent report of nanotechnology research, unique nanostructures and techniques have been used to bring innovative developments to current glucose sensors. However, there are still a lot of challenges ahead with respect to utilization in the human body, before the commercialization of these techniques is possible. Most glucose sensors based on novel materials have been limited due to their poor biocompatibility, high cost, and very time intensive preparation processes.This review discussed the selective reports on the fabrication and recent developments of enzymatic and non-enzymatic glucose sensors and their future challenges during the period spanning mid of 2006 to beginning of 2016.
Journal of The Electrochemical Society, 2018
A new approach was developed using a combination of a conducting polymer; poly(3,4-ethylenedioxythiophene) (PEDOT) with the electrochemically produced polymer of N-ferrocenyl-3-(1H-pyrrol-1-yl)aniline, (PFcPyBz) layer for the enzyme scaffolding resulting in excellent analytical parameters. To organize such a surface, graphite electrode was coated with a PEDOT layer and it was used as a transducer for electrochemical deposition of the polymer of a newly synthesized FcPyBz monomer. Using a PEDOT layer as the working electrode improved localization of the PFcPyBz on the transducer surface while enhancing the biosensor performance. A simple binding of glucose oxidase (GOx) as a test enzyme on this new polymeric platform was achieved using glutaraldehyde (GA) as the cross linker. The low limit of detection and high sensing sensitivity on glucose for the biosensor are estimated as 54 μM and 112.2 μA/mMcm 2 , respectively. The surface characterizations of the modified electrodes were investigated by cyclic voltammetry (CV), attenuated total reflectance-fourier transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM) techniques. Finally, different kinds of beverages were tested for sensor reliability with high accuracy. A well-known disorder, diabetes mellitus occurs via an increase in glucose concentration in human blood. Since it is spreading worldwide , its careful and precise detection gained importance to reduce the threat. 1,2 Mirroring the importance of the disease is the worldwide interest leading to publishing a number of articles per year. These developments have opened ways to the wide array of emerging applications in glucose biosensors. Development of the glucose oxidase based enzyme biosensors by different immobilization techniques on various kind of electrodes had been studied for several decades. 3,4 Conjugated polymers (CPs) promise to advance a number of real-world technologies. Of these applications, they are particularly attractive for uses in enzyme biosensors for environmental and health monitoring. Their unique properties such as high electrical conductivity, ease of preparation and good environmental and chemical stability have motivated the use of CPs in the form of thin films for biosensors. 5,6 CP based biosensors bring simple, accurate, reliable and low-cost determination of various analytes and act as a very effective analytical tool in the multiple areas. This description is also supported by a number of researchers using the CPs as an immobilization architecture. 7-10 PEDOT has been reported to exhibit superior stability in conductivity compared to other available polymers and this property prompted us to use the PEDOT film as a transducer in order to obtain a more stable scaffolding for the glucose sensor. Brett and co-workers developed a PEDOT/poly (methylene blue) (PMB) modified glassy carbon electrode (GCE) for a GOx-based biosensor. 11 PEDOT films generated on top of PMB modified bare electrode was used to enhance the stability of PMB modified electrode. The proposed sensing architecture (GOx/PEDOT/PMB/GCE) showed better biosensor performance than the ones for GOx/GCE and GOx/PEDOT/GCE biosensors. In another work, Si reported a simple synthesis of a hybrid film by elec-tropolymerizing 3,4-ethylenedioxythiophene (EDOT) on nanoporous gold (NPG) for applications in amperometric glucose biosensors. 12 They finally concluded that the NPG/PEDOT/GOx biosensor prepared by optimum film thickness is appropriate for effective substrate diffusing. PEDOT is also used as the working electrode for glucose sensing by Ho and co-workers. 13 In this work, PEDOT and ferrocene (Fc) containing polymer were used for not only reducing the working potential but also for improving the stability of the sensor. Moreover, after the invention of the Fc molecule in 1951, scientist paid attention to this sandwich like molecule in many other research areas. 14,15 A huge number of molecules containing Fc moiety were designed and assessed for their possible use in glucose sensing applications. 16,17 Elec-trodeposited copolymer of pyrrole and ferrocene carboxylate modified pyrrole p(Py-FcPy), 18 co-deposition of 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) aniline (SNS-NH 2) and 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl) amidoferrocenyldithiophosphonate (SNS-NH2-Fc) 19 and copolymer of O-4-(1H-pyrrol-1-yl)-ferrocenyldithiophosphonate (TPFc) with 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)butane-1-amine (TPA) 20 are the examples of the conjugated polymer based electron-mediating support materials for developing GOx immobilized electrodes. Under the light of this, this work will show a significant way to create CPs-based glucose biosensors exhibiting selective responses to a target analyte. Such approach predominantly includes functional-ization of PEDOT bearing surface with newly synthesized Fc moiety containing polymer. In this report, for the first time a PEDOT transducer was designed and a new one-pot synthesized ferrocene containing monomer was electrochemically deposited on a well-known polymer (PEDOT) surface for glucose sensing. Without the PEDOT layer it was difficult to coat PFcPyBz layer on the bare graphite surface. For this reason, the electrode surface is first modified with PEDOT and then coated with PFcPyBz. We described the importance and effect of CPs in biosensor construction that was highlighted in our previous works. 21,22 However, need for a promising analytical devices for glucose sensing with high accuracy and sensitivity has motivated us to design a new sensing system. Designing of the new surface in this study, a highly sensitive and reliable glucose sensor was developed with the help of glucose oxidase (GOx), as a model enzyme. Detailed optimization studies, surface characterization of the polymer layers and the amperomet-ric characterization were performed. Additionally, the testing of the biosensor was conducted using different kinds of commercial beverages. Experimental Chemicals and instrumentation.-All chemicals which were used for monomer synthesis and electrochemical polymerization, were purchased from Aldrich and used without further purification. Materials used for biosensor construction were also obtained from Aldrich. Glucose oxidase enzyme used in this study was (GOx, β-D-glucose: oxygen 1-oxidoreductase, EC 1.1.3.4, 17300 units/g solid) from A. Niger. Electrochemical polymerizations of the EDOT and the FcPyBz) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 144.122.34.94 Downloaded on 2018-12-27 to IP