Potentiometric Glucose Biosensor Research Articles

A Facile Fabrication of a Potentiometric Arrayed Glucose Biosensor Based on Nafion-GOx/GO/AZO.

In this study, the potentiometric arrayed glucose biosensors, which were based on zinc oxide (ZnO) or aluminum-doped zinc oxide (AZO) sensing membranes, were fabricated by using screen-printing technology and a sputtering system, and graphene oxide (GO) and Nafion-glucose oxidase (GOx) were used to modify sensing membranes by using the drop-coating method. Next, the material properties were characterized by using a Raman spectrometer, a field-emission scanning electron microscope (FE-SEM), and a scanning probe microscope (SPM). The sensing characteristics of the glucose biosensors were measured by using the voltage–time (V-T) measurement system. Finally, electrochemical impedance spectroscopy (EIS) was conducted to analyze their charge transfer abilities. The results indicated that the average sensitivity of the glucose biosensor based on Nafion-GOx/GO/AZO was apparently higher than that of the glucose biosensor based on Nafion-GOx/GO/ZnO. In addition, the glucose biosensor based on Nafion-GOx/GO/AZO exhibited an excellent average sensitivity of 15.44 mV/mM and linearity of 0.997 over a narrow range of glucose concentration range, a response time of 26 s, a limit of detection (LOD) of 1.89 mM, and good reproducibility. In terms of the reversibility and stability, the hysteresis voltages (VH) were 3.96 mV and 2.42 mV. Additionally, the glucose biosensor also showed good anti-inference ability and reproducibility. According to these results, it is demonstrated that AZO is a promising material, which could be used to develop a reliable, simple, and low-cost potentiometric glucose biosensor.

Fabrication of Potentiometric Glucose Biosensor Based on Two Variant Dimensions of Green Synthesized Silver Nanostructures as a Single Nanohybrid Compartment—A Green Approach

In this work, silver nanohybrids (AgNHs) comprising of two different dimensions of nanostructures i.e., nanorods (zero dimensions) and nanoparticles (one dimensions), are synthesised. As a green chemical approach, we have used the leaf extracts of Cassia occidentalis (coffee senna) for the synthetic protocol of these variant dimensions of nanostructures. The as synthesized nanostructures were explored for the fabrication of a nano-hybrid based potentiometric glucose biosensor. A conducting polymer, polypyrrole (PPy) is used for the strong adsorption of the nanohybrid on the graphite (Gr) electrode. The resulting composite matrix (Gr/PPy/AgNHs) is further modified with glucose oxidase (GOx) enzyme to obtain Gr/PPy/AgNHs/GOx biosensor for the electrochemical detection of glucose. The synergetic effect of the materials employed in development of bio-electrode resulted in an efficient glucose biosensor with a low detection limit (55.3 μM), high sensitivity (69.72 μAmM –1cm–2) and a wide linear range of 0.2–29 mM. These results validate a successful electrochemical sensor with superior analytical performance in comparison to sensors cited in literature. The proposed biosensor also exhibits good storage stability, reproducibility and remains unaffected by some of the common interferents present in the biological sample. The developed biosensor is also evaluated for glucose analysis in real samples with a high percentage recovery (97%) thus validating the possibility of its usage in biomedical applications.

Facile synthesis of multisegment Au/Ni/Au nanowire for high performance electrochemical glucose sensor

This paper reported an electrochemical potentiometric glucose biosensor, developed by immobilizing glucose oxidase on an electrode consisting of Au/Ni/Au nanowires. Electrochemically deposited nanowires are bridged between two gold electrodes. Field emission scanning electron microscope (FESEM) and energy-dispersive x-ray spectroscopy (EDS) are used for the morphological characterization of nanostructures. The device is tested by electrochemical potentiometric and simple IV measurement techniques. In order to check the glucose potentiometric response, nanowires are coated with enzyme, glucose oxidase which revealed a glucose dependant electrochemical response versus reference electrode (Ag/AgCl). Electrochemical response of the sensor is found to be linear in range of 0.5–10 mM. Fabrication of Au/Ni/Au nanowires by facile method will provide the opportunity for glucose biosensors to measure glucose by simple and direct technique.

Integrating a Plastic Glucose Biosensor Based on Arrayed Screen-Printed Electrodes Utilizing Magnetic Beads with a Microfluidic Device

In this study, a novel potentiometric glucose biosensor based on magnetic beads-Nafion-glucose oxidase/graphene oxide/aluminium-doped zinc oxide (MBs-Nafion-GOx/GO/AZO) membranes on a PET substrate with arrayed screen-printed electrodes (SPEs) was proposed. The morphologies, elemental analysis, and surface roughnesses of the sensing membranes were characterized. The sensing parameters of the biosensor were investigated by using the voltage-time (V-T) measurement system, which measured sensitivity, linearity, anti-interference ability, reversibility, temperature effect, and lifetime. A microfluidic device using polydimethylsiloxane (PDMS) was integrated with the V-T measurement system to analyze the response characteristics. The results under static solution and microfluidic flow conditions were compared. The results showed that the average sensitivity and linearity of the biosensor depended on the microfluidic flow rate. The best average sensitivity of the glucose biosensor based on MBs-Nafion-GOx/GO/AZO membranes was 20.35 mV/mM at a flow rate of $15~ \mu \text{L}$ /min.

Dynamic and Wireless Sensing Measurements of Potentiometric Glucose Biosensor Based on Graphene and Magnetic Beads

In this paper, the arrayed flexible pH sensor and glucose biosensor modified by magnetic beads and graphene were proposed. The ruthenium dioxide (RuO2) sensing films were deposited by radio frequency sputtering system and the screen-printed technique was used to construct the silver conducting wires and insulation layer of the RuO2 electrodes. In order to enhance performance of the pH sensor and glucose biosensor, the microfluidic device had been utilized and developed. In the measurement processes, the different pH and glucose solutions were investigated in various flow rates. According to the experimental results, the average sensitivity of the pH sensor was enhanced from 52.280 to 57.981 mV/pH and the average sensitivity of the RuO2/graphene/magnetic bead-GO x -Nafion glucose biosensor was enhanced from 10.628 to 13.541 mV/mM. With regard to the wireless sensing measurements, the wireless sensing system which complied the ZigBee standard was employed to transmit the signals of the pH or glucose measurements in this investigation, and the system consisted of the Xbee device, Arduino Mega 2560, readout circuit, pH or glucose biosensor and computer. According to the experimental results, the average sensitivity and linearity of the pH sensor were 51.063 mV/pH and 0.988, respectively, and the average sensitivity and linearity of the RuO2/graphene/magnetic bead-GO x -Nafion glucose biosensor were 11.005 mV/mM and 0.995, respectively.

Fabrication of Potentiometric Enzymatic Glucose Biosensor Based on Graphene and Magnetic Beads

In this paper, ruthenium dioxide (RuO2) electrodes were fabricated by radio frequency sputtering and screen-printed technique, and RuO2 sensing films could be as pH sensor to measure different pH solutions. The average sensitivity and linearity of pH sensor were 51.847 mV/pH and 0.987, respectively. A glucose biosensor could be prepared through casting glucose oxidase (GOx) on RuO2 electrode, so the flexible arrayed glucose biosensors modified by magnetic beads (MBs) and graphene (GR) were developed in this paper. In preparation processes, GR solution was first cast on the RuO2, then we introduced carbodiimide hydrochloride (EDC) to connect glucose oxidase (GOx) and MB by covalent bond. Finally, MBs-GOx-nafion composite was dropped on RuO2 to complete preparation of the RuO2/GR/MB-GOx-Nafion glucose biosensor. The electrochemical impedance spectra (EIS) was used to investigate the capability of electron transfer of the different electrodes, and it was found that the additions of MBs and GR which had excellent electric conductivity could decrease the electron transfer resistance ( $R_{\rm ct}$ ) from the experiment results. Besides, EIS could also be used to demonstrate whether the glucose biosensors had already been completely modified by MBs and GR through the different resistances of the biosensors. Furthermore, the glucose biosensor modified by MBs and GR had the superior performance, the average sensitivity and linearity of RuO2/GR/MB-GOx-Nafion glucose biosensor were 10.628 mV/mM and 0.998, respectively. After 28 days, RuO2/GR/MB-GOx-Nafion glucose biosensor still had relative sensitivity of 82.2%.

Potentiometric glucose biosensor based on core–shell Fe3O4–enzyme–polypyrrole nanoparticles

Core–shell Fe3O4–enzyme–polypyrrole (Ppy) nanoparticles with excellent magnetism and conductivity were successfully prepared via the surface modification and enzyme self-encapsulation within Ppy. A novel potentiometric glucose biosensor has been constructed by effectively attaching the proposed Fe3O4–enzyme–Ppy nanoparticles to the surface of the magnetic glassy carbon electrode (MGCE). The optimum biosensing conditions could be provided with polymerization time of pyrrole for 6h and 0.42mg immobilization amount of Fe3O4–enzyme–Ppy nanoparticles on MGCE. The performance of the developed glucose biosensor was evaluated and the results indicated that a sensitive glucose biosensor could be fabricated. The obtained glucose biosensor presents shorter response time (6s), wider linear range (0.5μM to 34mM), lower limit of detection (LOD, 0.3μM), high-selectivity monitoring of glucose and good stability (with about 98.1% of the initial response signal retained after 20 days). The analytical application of the glucose biosensor confirms the feasibility of glucose detection in serum sample.

Indirect Determination of Mercury Ion by Inhibition of a Glucose Biosensor Based on ZnO Nanorods

A potentiometric glucose biosensor based on immobilization of glucose oxidase (GOD) on ZnO nanorods (ZnO-NRs) has been developed for the indirect determination of environmental mercury ions. The ZnO-NRs were grown on a gold coated glass substrate by using the low temperature aqueous chemical growth (ACG) approach. Glucose oxidase in conjunction with a chitosan membrane and a glutaraldehyde (GA) were immobilized on the surface of the ZnO-NRs using a simple physical adsorption method and then used as a potentiometric working electrode. The potential response of the biosensor between the working electrode and an Ag/AgCl reference electrode was measured in a 1mM phosphate buffer solution (PBS). The detection limit of the mercury ion sensor was found to be 0.5 nM. The experimental results provide two linear ranges of the inhibition from 0.5 × 10−6 mM to 0.5 × 10−4 mM, and from 0.5 × 10−4 mM to 20 mM of mercury ion for fixed 1 mM of glucose concentration in the solution. The linear range of the inhibition from 10−3 mM to 6 mM of mercury ion was also acquired for a fixed 10 mM of glucose concentration. The working electrode can be reactivated by more than 70% after inhibition by simply dipping the used electrode in a 10 mM PBS solution for 7 min. The electrodes retained their original enzyme activity by about 90% for more than three weeks. The response to mercury ions was highly sensitive, selective, stable, reproducible, and interference resistant, and exhibits a fast response time. The developed glucose biosensor has a great potential for detection of mercury with several advantages such as being inexpensive, requiring minimum hardware and being suitable for unskilled users.

Highly efficient potentiometric glucose biosensor based on functionalized InN quantum dots

We present a fast, highly sensitive, and efficient potentiometric glucose biosensor based on functionalized InN quantum-dots (QDs). The InN QDs are grown by molecular beam epitaxy. The InN QDs are bio-chemically functionalized through physical adsorption of glucose oxidase (GOD). GOD enzyme-coated InN QDs based biosensor exhibits excellent linear glucose concentration dependent electrochemical response against an Ag/AgCl reference electrode over a wide logarithmic glucose concentration range (1 × 10−5 M to 1 × 10−2 M) with a high sensitivity of 80 mV/decade. It exhibits a fast response time of less than 2 s with good stability and reusability and shows negligible response to common interferents such as ascorbic acid and uric acid. The fabricated biosensor has full potential to be an attractive candidate for blood sugar concentration detection in clinical diagnoses.

Potentiometric glucose biosensing using camphor sulfonic acid doped polyaniline

In this work, we explored the possibility of developing an enzymatic potentiometric glucose biosensor using polyaniline–camphorsulfonic acid–glucose oxidase (PANI–CSA–GOD) composite films. Glucose oxidase was covalently immobilized on the polyaniline–camphorsulfonic acid modified electrode that was used as a potentiometric sensor matrix. The PANI–CSA–GOD transducer responded linearly to glucose molecules in the concentration range of 1 to 50 mM and the sensitivity was found to be 0.09 mV mM−1. The modified electrode showed excellent sensitivity and better selectivity in the presence of some common interfering molecules.

A fast and sensitive potentiometric glucose microsensor based on glucose oxidase coated ZnO nanowires grown on a thin silver wire

In this study, a potentiometric glucose biosensor was fabricated by immobilization of glucose oxidase on to zinc oxide nanowires. Zinc oxide nanowires with 250–300 nm diameters and approximately 1.2 μm lengths were grown on the surface of silver wires with a diameter of 250 μm. Glucose oxidase (GOD) was electrostatically immobilized on the surface of the well aligned zinc oxide nanowires resulting in sensitive, selective, stable and reproducible glucose biosensors. The potentiometric response vs. Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (0.5–1000 μM) suitable for intracellular glucose detection. By applying a membrane on the sensor the linear range could be extended to 0.5 μM to 10 mM, which increased the response time from less than 1 to 4 s. On the other hand the membrane increased the sensor durability considerably. The sensor response was unaffected by normal concentrations of common interferents with glucose sensing such as uric acid and ascorbic acid.

STUDY ON THE POTENTIOMETRIC GLUCOSE BIOSENSOR BASED ON THE SnO2/ITO/PET

A potentiometric glucose biosensor based on a SnO2/ITO/PET substrate is presented in this study. The sensing membrane of SnO2 is coated on ITO/PET substrate by utilized radio frequency (RF)-sputtering method of semiconductor fabrication. The potentiometric glucose biosensor is established on an FET-type pH sensor. Therein, the glucose oxidase (GOD) and chitosan/multi-wall carbon nano-tubes (chitosan/MWCNTs) are immobilized by 3-glycidoxypropyl trimethoxysilane (3-GPTS). Finally, the drift characteristic and calibration curve of the potentiometric pH sensor and potentiometric glucose biosensor is discussed in the following article. We find the nonideal effect of device reduced significantly, due to the coating of SnO2 thin film.

Potentiometric Multisensor Based on Ruthenium Dioxide Thin Film With a Bluetooth Wireless and Web-Based Remote Measurement System

This study reports the preparation and analysis of a potentiometric multisensor for detecting pH, uric acid, and glucose levels. The pH sensor was based on a ruthenium dioxide (RuO2) sensing membrane. The potentiometric uric acid and glucose biosensors consisted of immobilized uricase and glucose oxidase (GOD) enzymes on the RuO2 sensing membrane. The ruthenium dioxide sensing membrane was first deposited on silicon and polyethylene terephthalate (PET) substrates using a sputtering system. A graphical measurement interface for the multisensor was also designed using National Instrument LabVIEW software. The potentiometric uric acid biosensor based on a ruthenium dioxide membrane on PET and silicon substrates can be determined in the linear ranges from 2 to 8 mg/dl with a 0.995 and 0.998 linear regression, respectively. In addition, the potentiometric glucose biosensor based on a ruthenium dioxide thin film on PET and silicon substrates shows that the measurement ranges from 40 to 360 mg/dl at sensitivities of 0.348 and 0.468 mV(mg/dl)-1, respectively. This study also investigates wireless monitoring (Bluetooth) and remote monitoring (Web-based) of the multisensor's measurement system and integrates the utility of the developed sensors for homecare or healthcare in the future.

Preliminary investigations on a glucose biosensor based on the potentiometric principle

In this study, an electron mediator and a simple immobilization process are adopted to fabricate a potentiometric glucose biosensor. The enzyme and the electron mediator are immobilized on the surface of tin oxide (SnO 2)/indium tin oxide (ITO) glass using a covalent bond method to develop a disposable potentiometric glucose biosensor. The SnO 2/ITO glass is a pH sensor fabricated by depositing SnO 2 thin films onto an ITO glass. The glucose oxidase (GOD) and the electron mediator (ferrocenecarboxylic acid, FcA) are co-immobilized on the SnO 2/ITO glass using 3-glycidyloxypropyltrimethoxysilane (GPTS). This work investigates the coimmobilization of GOD and FcA as a useful approach for enlarging the dynamic range to a glucose concentration of 360 mg/dl, and for improving linearity and sensitivity of the fabricated glucose biosensor. The experimental results indicate that the optimal weight ratio of GOD to FcA is 1:1. The output signal is associated with the pH of the measurement environment and the optimal pH value is pH 7.5.

Potentiometric biosensor for urinary glucose level monitoring

Monitoring of urinary glucose level is of great interest in health control. As a fast and accurate means to achieve this purpose, a potentiometric glucose biosensor based on SnO2 film was developed. The optimum manufacturing conditions and the functional characteristics of the biosensor were established. The n-type Sb-doped SnO2 semiconductor film properties were characterized using electrochemical impedance spectroscopy. Measurements on urine samples yielded results that are in good agreement with those obtained with the Nylander method and more accurate than those obtained with a test paper. Taking into account that urine samples do not need pretreatment and that by the renewal of the enzyme membrane the stability period of the biosensor may be prolonged over 8 days, it may be used in continuous flux, too. © 2000 John Wiley & Sons, Inc. Lab Robotics and Automation 12:291–295, 2000