Xanthine Biosensor Research Articles

Electrochemical xanthine biosensor based on carbon nanofiber and ferrocene carboxylic acid for the assessment of fish freshness

Electrochemical xanthine biosensor based on carbon nanofiber and ferrocene carboxylic acid for the assessment of fish freshness

Lanthanum Sulfide Nanorods Modified Glassy Carbon Electrode as Non-Enzymatic Biosensor for Xanthine

Xanthine detection is crucial for the diagnosis of metabolic disorders like xanthinuria and gout. Xanthinuria is due to xanthine stones in the urinary tract. Earlier detection of xanthine levels in human blood can minimize the risks. In this research, a non-enzymatic xanthine sensor is fabricated by depositing different concentrations of lanthanum sulfide nanoparticles on a glassy carbon electrode (GCE). Lanthanum sulfide (La2S3) nanorods are synthesized by a simple hydrothermal method and characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The effect of pH, scan rates, and xanthine concentration on the peak current is examined. La2S3-modified GCE shows good conductivity, a large surface area, fast electron transfer, and promising sensing capability for xanthine detection. The highest anodic peak for xanthine is observed at a 1 mV s−1 scan rate. The la2S3-based sensor exhibits a limit of detection (LOD) of 1.2 μM and xanthine recovery of up to 99.3%. The designed sensing system demonstrates the potential for xanthine detection in blood serum samples. The proposed sensor exhibits excellent efficiency due to fast electron transfer and good stability of La2S3 nanorods.

Nanomaterial-Doped Xerogels for Biosensing Measurements of Xanthine in Clinical and Industrial Applications.

First-generation amperometric xanthine (XAN) biosensors, assembled via layer-by-layer methodology and featuring xerogels doped with gold nanoparticles (Au-NPs), were the focus of this study and involved both fundamental exploration of the materials as well as demonstrated usage of the biosensor in both clinical (disease diagnosis) and industrial (meat freshness) applications. Voltammetry and amperometry were used to characterize and optimize the functional layers of the biosensor design including a xerogel with and without embedded xanthine oxidase enzyme (XOx) and an outer, semi-permeable blended polyurethane (PU) layer. Specifically, the porosity/hydrophobicity of xerogels formed from silane precursors and different compositions of PU were examined for their impact on the XAN biosensing mechanism. Doping the xerogel layer with different alkanethiol protected Au-NPs was demonstrated as an effective means for enhancing biosensor performance including improved sensitivity, linear range, and response time, as well as stabilizing XAN sensitivity and discrimination against common interferent species (selectivity) over time-all attributes matching or exceeding most other reported XAN sensors. Part of the study focuses on deconvoluting the amperometric signal generated by the biosensor and determining the contribution from all of the possible electroactive species involved in natural purine metabolism (e.g., uric acid, hypoxanthine) as an important part of designing XAN sensors (schemes amenable to miniaturization, portability, or low production cost). Effective XAN sensors remain relevant as potential tools for both early diagnosis of diseases as well as for industrial food monitoring.

Wiring Xanthine Oxidase Using an Osmium‐Complex‐Modified Polymer for Application in Biosensing.

AbstractXanthine is a metabolite of interest as a medical and food freshness biomarker. We modified a screen‐printed electrode to detect this analyte by co‐entrapping xanthine oxidase (XOD) and an Os‐complex redox polymer over carbon nanotubes. In nature, XOD transfers its electrons to oxygen in solution. We demonstrate that the introduction of the redox polymer allows routing the electrons efficiently to the electrode surface, even under air‐saturated conditions, enabling superior catalytic current and sensing performance. The bioanode was optimized by adjusting the electrode materials and the ratio of enzyme to redox polymer. The impacts of pH and ionic strength of the electrolyte on the sensor performance were also studied. We found that these variables can affect the electrostatic interaction between the enzyme and the redox polymer, and therefore impact the catalytic current extracted from xanthine oxidation. The XOD‐bioanode design was combined with a bi‐enzymatic cathode operating on glucose to demonstrate a biofuel cell (BFC). The resulting device could generate a power output of 16.56 μW cm−2 at 0.25 V and an open‐circuit voltage (OCV) of 0.50 V using 500 μM xanthine as biofuel. The proposed xanthine/glucose BFC showed promising features for application as a self‐powered xanthine biosensor.

An interference-free new xanthine biosensor based on immobilized enzyme-nanogold conjugate on carbon nanotube doped poly(3,4-Ethylenedioxythiophene) composite film

A new design of biosensor based on polymeric nano(bio)composite has been proposed for the selective detection of xanthine to be used in the clinical analysis as well as food quality control. The xanthine oxidoreductase (XOR) gene ofPseudomonas aerogenosastrain CEBP1 wascloned to obtainpurifiedenzyme through affinity chromatography. fMWCNTdoped PEDOTwas electrodeposited on the working electrodeto enhance the sensitivity and selectivity of the biosensor. Bio-synthesized gold nanoparticles conjugated XOR (Au-XOR) was covalently immobilized on the polymeric nanocomposite. The enzymatic activity was enhanced 1.12 times with increased substrate affinity. The surface morphology and structural properties of the polymeric layer were investigated using SEM, FESEM, TEM. Electrochemical characteristics were performed by cyclic voltammetry, differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy. Xanthine was oxidized (pH 7.0) on the uniquely designed polymeric nano(bio)composite modified electrode at a lower anodic potential of + 0.446 V vs. Ag/AgCl (3 M NaCl)at optimized DPV conditions. The simple, newly designed Au-XOR/fMWCNT-PEDOT/GCE exhibited interference-free reproducibility and stability (∼4 months) with excellent sensitivity of 16.075 µA.µM−1.cm−2for the quantification of xanthine in biological samples such as blood, tissue, urine. The applicability of thebiosensor was validatedby comparing the sensing results for the real biological fluidic solutions with HPLC data (RE = 0.5–3.1%).

An improved amperometric determination of xanthine with xanthine oxidase nanoparticles for testing of fish meat freshness

The nanoparticles of xanthine oxidase (XODNPs) were prepared by desolvation method and characterized by transmission electron microscopy(TEM) and Fourier transform Infra-red spectroscopy(FTIR). These XODNPs were immobilized directly onto surface of Au electrode via covalent bond. An improved amperometric xanthine biosensor was fabricated using XODNPs modified Au electrode, as working electrode (WE), Ag/AgCl as reference electrode and Pt wire as auxiliary electrode connected through potentiostat.The biosensor showed optimum current at 0.25 V within 5 s, at pH 7.0 and 35 °C.The working range of biosensor was 0.01–1.0 μM with a limit of detection of 0.01 μM.The % recovery of added xanthine (1 and 5 μM) was 94.1 ± 0.2 and 94.8 ± 0.31 respectively. Within and between batch coefficient of variation (CV) were <2% & < 2.5% respectively. A good correlation (R2 = 0.996) was obtained between xanthine contents in various fish meat,as measured by the present biosensor and the standard bienzymic colorimetric method. The biosensor was employed for measuring xanthine level in fish meat at different stages of storage to test its freshness. The XODNPs modified Au electrode was stored dry at 4 °C for 2 months.

Nanohybrid electrochemical enzyme sensor for xanthine determination in fish samples.

An amperometric biosensor for xanthine was designed, based on covalent immobilization of xanthine oxidase (XO) of Bacillus pumilus RL-2d onto a screen-printed multi-walled carbon nanotubes gold nanoparticle-based electrodes (Nano-Au/c-MWCNT). The carboxyl groups at the electrode surface were activated by the use of 1-Ethyl-3-(3-dimethylaminopropyl carbodiimide) (EDC) and N-hydroxysuccinimide (NHS). The working electrode was then coated with 6 μL of xanthine oxidase (0.273 U/mg protein). The cyclic voltammetry (CV) study was done for the characterization of the sensor using [K3Fe(CN)6] as an artificial electron donor. The sensitivity (S) and the limit of detection (LOD) of the biosensor were 2388.88 µA/cm2/nM (2.388 µA/cm2/µM) and 1.14nM, respectively. The developed biosensor was used for determination of fish meat freshness.

Construction of novel nonenzymatic Xanthine biosensor based on reduced graphene oxide/polypyrrole/CdO nanocomposite for fish meat freshness detection

A novel nonenzymatic voltammetric Xanthine biosensor was constructed based on a three-dimensional porous nanocomposite of reduced graphene oxide/polypyrrole/CdO nanocomposite modified glassy carbon electrode (GCE/rGO/PPy/CdO) for measuring of Xanthine. The structure and morphology of rGO/PPy/CdO nanocomposites were characterized by field emission scanning microscopy, Raman spectroscopy, X-ray diffraction, UV–vis spectroscopy, Fourier transform infrared and X-ray photoelectron spectroscopy. The GCE/rGO/PPy/CdO based biosensor exhibited excellent electrocatalytic activity and high stability for Xanthine oxidation. Under optimized conditions, the linearity between the current response and the Xanthine concentration was obtained in the range of 1–800 µM with a detection limit of 0.11 μM (S/N = 3). The biosensor was used to determine the Xanthine in fish meat with satisfactory results.

Construction of a novel xanthine biosensor using zinc oxide (ZnO) and the biotemplate method for detection of fish freshness

In the food industry, fish is a product that has a short shelf life, and xanthine has attracted significant attention as an indicator of the freshness of fish.

Magnetite Nanospheres as Carbon Paste Electrode Modifier for Xanthine Biosensor

Magnetite Nano spheres was prepared and used to fabricate a modified carbon paste electrode as xanthine biosensor and applied to determine inhibition kinetics of Syzygium polyanthum extract toward xanthine oxidase (XO). The magnetite Nano spheres was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical behaviour of xanthine was investigated by immobilizing the XO on the surface of carbon paste electrode (CPE), modified magnetite Nano spheres-CPE (MCPE), and modified 2,3-dimethoxy-5-metil-1,4-benzoquinone (Q0)-CPE (QCPE) employing cyclic voltammetry (CV) technique. The result showed that the MCPE was the best electrode to determine the analytical performance under optimum condition, based on lower limit of detection (0.005 mM), wider linearity range (0.01-1 mM with R2 = 99.24%), and higher sensitivity (5.16 µM-1) than the two other electrodes (CPE and QCPE). The MCPE successfully improve the analytical performance on xanthine biosensor and to be applied for determining inhibition kinetics of S. polyanthum extract. Inhibition kinetics of the extract has caused increase of KM and VMAX (IMAX) constant. Based on the result, the type of inhibition kinetics was a competitive inhibition.

Electrochemical xanthine biosensor based on zinc oxide nanoparticles‒multiwalled carbon nanotubes‒1,4-benzoquinone composite

Zinc oxide nanoparticles (ZnONPs), multiwalled carbon nanotubes (MWCNTs) and 1,4-benzoquinone (BQ) dispersed in chitosan (CS) matrix were used to construct a xanthine biosensor. Xanthine oxidase (XOx) was immobilized onto BQ-MWCNTs-ZnO–CS composite modified glassy carbon electrode (GCE) using glutaraldehyde as the crosslinking agent. The parameters of the construction process and the experimental variables for the biosensor were optimized. The xanthine biosensor showed optimum response within 10 s, and the sensitivity was 39.4 μA/mMcm 2 at +0.25 V (vs. Ag/AgCl). The linear working range of the biosensor was found to be 9.0×10 −7 - 1.1×10 −4 M with a detection limit of 2.1×10 -7 M. The biosensor exhibited good long-term stability and reproducibility. The presented biosensor was also used for monitoring the freshnesses of chicken and beef flesh.

Magnetite Nanospheres As Modifier of Carbon Paste Electrode for Determination of Inhibition Kinetics of Syzygiumpolyanthum extract Toward Xanthine Oxidase

Magnetite nanospheres was prepared and used to fabricate a modified carbon paste electrode as xanthine biosensor and applied to determine inhibition kinetics of Syzygium polyanthum extract toward xanthine oxidase (XO). The magnetite nanospheres was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical behavior of xanthine was investigated by immobilizing the XO on the surface of carbon paste electrode (CPE), modified magnetite nanospheres-CPE (MCPE), and modified 2,3-dimethoxy-5-metil-1,4-benzoquinone (Q0)-CPE (QCPE) employing cyclic voltammetry (CV) technique. The result showed that the MCPE was the best electrode to determine the analytical performance under optimum condition, based on lower limit of detection (0.005 mM), wider linearity range (0.01-1 mM with R2= 99.24%), and higher sensitivity (5.16 µM-1) than the two oter electrodes (CPE and QCPE). The MCPE successfully improve the analytical performance on xanthine biosensor and to be applied for determining inhibition kinetics of S. polyanthum extract. Inhibition kinetics of the extract has caused increase of KM and VMAX (IMAX) constant. Based on the result, the type of inhibition kinetics was a competitive inhibition.

Novel electrochemical xanthine biosensor based on chitosan–polypyrrole–gold nanoparticles hybrid bio-nanocomposite platform

The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the amperometric xanthine biosensor, chitosan–polypyrrole–gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity. Electrochemical studies were carried out by the modified electrode with immobilized xanthine oxidase on it, after which the biosensor was tested to ascertain the optimization parameters. The Biosensor exhibited a very good linear range of 1–200 μM, low detection limit of 0.25 μM, average response time of 8 seconds, and was not prone to significant interference from uric acid, ascorbic acid, glucose, and sodium benzoate. The resulting bio-nanocomposite xanthine biosensor was tested with fish, beef, and chicken real-sample measurements.

Amperometric biosensors based on carboxylated multiwalled carbon nanotubes-metal oxide nanoparticles-7,7,8,8-tetracyanoquinodimethane composite for the determination of xanthine

A comparison of the analytical performances of two xanthine biosensors, based on the use of different metal oxide nanoparticles (MONPs: Co3O4 or Fe3O4)-modified carboxylated multiwalled carbon nanotubes (c-MWCNTs)-7,7′,8,8′-tetracyanoquinodimethane (TCNQ)-chitosan (CHIT) composite, is discussed. Xanthine oxidase (XOD) enzyme was covalently attached to c-MWCNTs/MONPs/TCNQ/CHIT/GCE via N-ethyl-N′-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxy succinimide (NHS) chemistry and the electrode surface was further modified with Nafion in order to minimize the effect of possible interfering substances. The results showed that analytical performance of the Fe3O4 based biosensor was better than the Co3O4 based biosensor. The linear working range, limit of detection and sensitivity were found to be 1.9×10−6–2.3×10−4M, 0.20μM (S/N=3), 25.07μAmM−1cm−2 for the Fe3O4 based biosensor and 1.9×10−6–1.2×10−4M, 0.36μM (S/N=3), 13.24μAmM−1cm−2 for the Co3O4 based biosensor, respectively. The purposed biosensors were applied in the determination of xanthine in coffee samples, and satisfactory results were obtained.

CONSTRUCTION OF AN ELECTROCHEMICAL XANTHINE BIOSENSOR BASED ON GRAPHENE/COBALT OXIDE NANOPARTICLES/CHITOSAN COMPOSITE FOR FISH FRESHNESS DETECTION

Xanthine biosensor based on glassy carbon electrode (GC) modified with graphene (GR), Co 3 O 4 nanoparticles and chitosan (CH) composite was fabricated. Xanthine oxidase (XAO) solution was dropped on the surface of Co 3 O 4 /CH/GR/GC and electrode was placed in saturated glutaraldehyde vapor for the crosslinking of the enzymes. The modified electrode was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. Under the optimized experimental conditions, xanthine was detected in the concentration range from 5.0×10 -7 to 8.0×10 -5 M with a detection limit of 2.0×10 -7 M. The low Michaelis–Menten constant (0.17 mM) suggested enhanced enzyme affinity for the immobilized enzyme as compared to previously reported xanthine biosensors. Moreover, the biosensor exhibited some advantages, such as short response time (10 s), high sensitivity (6.58 μA/mM or 74.8 µA/mMcm 2 ) and good reproducibility (RSD = 1.2%). The suitability of the device was verified by xanthine assay in a fish meat. The biosensor provide to be a reliable, easy, fast and economical method for the evaluation of fish freshness.

Preparation, Characterization and Electrochemical Application of Graphene‐metallic Nanocomposites

AbstractThree different Graphene‐Metallic (Graphene‐Me) nanocomposites – Graphene‐Silver (Graphene‐Ag), Graphene‐Gold (Graphene‐Au) and Graphene‐Platinum (Graphene‐Pt) nanocomposites – were prepared and characterized. The electrochemical performances of these nanocomposites were tested by incorporating them with glassy carbon paste electrode (GCPE) and used them in biofuel cells (BFC) and as amperometric xanthine biosensor transducers. Present work contains the first application of Graphene‐Au and Graphene‐Ag nanocomposite in BFCs and also first application of these Graphene‐Me nanocomposites in xanthine biosensors. Considering BFC, power and current densities were calculated as 2.03 µW cm−2 and 167.46 µA cm−2 for the plain BFC, 3.39 µW cm−2 and 182.53 µA cm−2 for Graphene‐Ag, 4.43 µW cm−2 and 230.15 µA cm−2 for Grapehene‐Au and 6.23 µW cm−2 and 295.23 µA cm−2 for Graphene‐Pt nanocomposite included BFCs respectively. For the amperometric xanthine biosensor linear ranges were obtained in the concentration range between 5 µM and 50 µM with the RSD (n=3 for 30 µM xanthine) value of 4.28 % for plain xanthine biosensor, 3 µM and 50 µM with the RSD (n=3 for 30 µM xanthine) value of 9.37 % for Graphene‐Ag, 5 µM to 20 µM with the RSD (n=3 for 5 µM xanthine) value of 9.00 % and 30 µM to 70 µM with the RSD (n=3 for 30 µM xanthine) value of 8.80 % for Grapehene‐Au and 1 µM and 70 with the the RSD (n=3 for 30 µM xanthine) value of 2.59 % for Grapehene‐Pt based xanthine biosensors respectively.

Xanthine biosensor based on XO/AuNP/PtNP/MWCNT hybrid nanocomposite modified GCPE

A new xanthine (X) biosensors based on a hybrid nanocomposite containing multi-walled carbon nanotubes (MWCNT), Pt nanoparticles (PtNP) and gold nanoparticle (AuNP) was presented. X biosensor was fabricated by dropping AuNP/PtNP/MWCNT onto xanthine oxidase (XO) modified glassy carbon paste electrode (GCPE). Resulted XO/AuNP/PtNP/MWCNT/GCPE biosensor showed two linearity between 2.0 and 50 µM and 0.25 and 6.0 mM for X. RSD value was calculated as 2.46 (n = 5). Finally, the biosensor was applied to the X detection in synthetic serum samples and good recovery value was obtained.

Novel amperometric xanthine biosensor based on xanthine oxidase immobilized on electrochemically polymerized 10-[4H-dithieno(3,2-b:2′,3′-d)pyrrole-4-yl]decane-1-amine film

In this paper, a novel amperometric xanthine (X) biosensor is constructed by xanthine oxidase (XOx) immobilization on the pencil graphite electrode (PGE). Xanthine oxidase is immobilized using glutaraldehyde (GA) on the electrochemically polymerized conducting polymer film. The detection of xanthine is based on its consumed amount due to the enzymatic reaction of xanthine oxidase. The effects of polymer thickness, applied potential, pH, and temperature were investigated and optimum parameters were found to be five cycles, +5V, +0.5V and 30°C, respectively. Storage stability, operation stability of the enzyme electrode, and effect of interferant substances on the amperometric response were also studied. In order to verify the applicability of proposed biosensor, fabricated electrode was used to measure the xanthine concentration in chicken meat samples. The present xanthine biosensor with high selectivity, sensitivity, and stability is promising for practical applications.

Electrochemical biosensor based on REGO/Fe3O4 bionanocomposite interface for xanthine detection in fish sample

In this study, xanthine molecules which can serve as an indicator of meat spoilage were determined using a novel and sensitive amperometric xanthine biosensor. Biosensor was developed by preparing a nanocomposite film that was constructed by embedding reduced expanded graphene oxide (REGO) sheets decorated with iron oxide (Fe3O4) nanoparticles into poly(glycidyl methacrylate-co-vinylferrocene) (P(GMA-co-VFc)) phase, and by covalent immobilization of Xanthine oxidase (XOD) on the surface of P(GMA-co-VFc)/REGO-Fe3O4 nanocomposite film. Bio-analytical optimal experimental conditions such as response time, linear range, operation and storage stability, working pH and temperature were studied. Current response of linear range was detected in the range of 2–36 μM with a sensitivity of 0.17 μA/M, response time of ∼3 s, and detection limit of 0.17 μM. The resulting bio-nanocomposite xanthine biosensor was subjected to fish real sample testings where 5, 8, 10, 13, 15, and 20 days-old fish samples’ xanthine content was measured. The developed biosensor was found to be applicable to real samples as a very reliable fish freshness controlling technique.

Construction of novel xanthine biosensor by using polymeric mediator/MWCNT nanocomposite layer for fish freshness detection

A novel nanocomposite host matrix for enzyme immobilization of xanthine oxidase was developed by incorporating MWCNT in poly(GMA-co-VFc) copolymer film. In the food industry fish is a product with a very low commercial life, and a high variability as well elevated level of xanthine is an important biomarker as a sign of spoilage. The fabricated process was characterized by scanning electron microscopy (SEM), and the electrochemical behaviors of the biosensor were characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The prepared enzyme electrodes exhibited maximum response at pH 7.0 and 45°C +0.35V and reached 95% of steady-state current in about ∼4s and its sensitivity was 16mAM−1. Linear ranges (2–28μM, 28–46 and 46–86μM), analytical performance and a low detection limit 0.12μM obtained from the xanthine biosensor gives reliable results in measuring xanthine concentration in the fish meat. All the results indicating that the resulting biosensor exhibited a good response to xanthine that was related to the addition of MWCNT in the polymeric mediator film which played an important role in the biosensor performance. In addition, the biosensor exhibited high good storage stability and satisfactory anti-interference ability.