scholarly journals Dispersed Conducting Polymer Nanocomposites with Glucose Oxidase and Gold Nanoparticles for the Design of Enzymatic Glucose Biosensors

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2173
Author(s):  
Natalija German ◽  
Almira Ramanaviciene ◽  
Arunas Ramanavicius
Keyword(s):  
Glucose Oxidase ◽  
Conducting Polymer ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Serum Samples ◽  
Glucose Determination ◽  
Constant Potential ◽  
Good Repeatability ◽  
Graphite Rod

Biosensors for the determination of glucose concentration have a great significance in clinical diagnosis, and in the food and pharmaceutics industries. In this research, short-chain polyaniline (PANI) and polypyrrole (Ppy)-based nanocomposites with glucose oxidase (GOx) and 6 nm diameter AuNPs (AuNPs(6 nm)) were deposited on the graphite rod (GR) electrode followed by the immobilization of GOx. Optimal conditions for the modification of GR electrodes by conducting polymer-based nanocomposites and GOx were elaborated. The electrodes were investigated by cyclic voltammetry and constant potential amperometry in the presence of the redox mediator phenazine methosulfate (PMS). The improved enzymatic biosensors based on GR/PANI-AuNPs(6 nm)-GOx/GOx and GR/Ppy-AuNPs(6 nm)-GOx/GOx electrodes were characterized by high sensitivity (65.4 and 55.4 μA mM−1 cm−2), low limit of detection (0.070 and 0.071 mmol L−1), wide linear range (up to 16.5 mmol L−1), good repeatability (RSD 4.67 and 5.89%), and appropriate stability (half-life period (τ1/2) was 22 and 17 days, respectively). The excellent anti-interference ability to ascorbic and uric acids and successful practical application for glucose determination in serum samples was presented for GR/PANI-AuNPs(6 nm)-GOx/GOx electrode.

scholarly journals Glucose Biosensor Based on Dendritic Gold Nanostructures Electrodeposited on Graphite Electrode by Different Electrochemical Methods

Chemosensors ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 188
Author(s):  
Almira Ramanaviciene ◽  
Natalija German ◽  
Asta Kausaite-Minkstimiene ◽  
Arunas Ramanavicius
Keyword(s):  
Glucose Oxidase ◽  
Limit Of Detection ◽  
Differential Pulse ◽  
Glucose Biosensor ◽  
Electrochemical Methods ◽  
Gold Nanostructures ◽  
Glucose Determination ◽  
One Step ◽  
Constant Potential ◽  
Good Repeatability

In this research, we have demonstrated a one-step electrochemical deposition of dendritic gold nanostructures (DGNs) on a graphite rod (GR) electrode without any template, seeds, surfactants, or stabilizers. Three electrochemical methods, namely, constant potential amperometry (CPA), pulse amperometry, and differential pulse voltammetry, were used for DGN synthesis on GR electrode and further application in enzymatic glucose biosensors. Formed gold nanostructures, including DGNs, were characterized by a field emission scanning electron microscopy. The optimal concentration of HAuCl4 (6.0 mmol L−1), duration of DGNs synthesis (400 s), electrodeposition potential (−0.4 V), and the best electrochemical method (CPA) were determined experimentally. Then the enzyme, glucose oxidase, was adsorbed on the surface of DGNs and covalently cross-linked with glutaraldehyde vapor. The enzymatic glucose biosensor based on DGNs electrodeposited at optimal conditions and modified with glucose oxidase showed a quick response (less than 3 s), a high saturation current (291 μA), appropriate linear range (up to 9.97 mmol L−1 of glucose, R2 = 0.9994), good repeatability (RSD 2.4, 2.2 and 1.5% for 2, 30, 97 mmol L−1 of glucose), low limit of detection (0.059 mmol L−1, S/N = 3) and good stability. Additionally, this biosensor could be successfully applied for glucose determination in real samples with good accuracy. These results proved the principle of enzymatic glucose biosensor development based on DGNs as the basis for further investigations.

scholarly journals Non-enzymatic sensor for determination of glucose based on PtNi nanoparticles decorated graphene

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Risheng Li ◽  
Xu Deng ◽  
Longfei Xia
Keyword(s):  
Limit Of Detection ◽  
High Sensitivity ◽  
Glucose Detection ◽  
Serum Samples ◽  
Time Curve ◽  
Current Time ◽  
Glass Carbon ◽  
Graphene Glass ◽  
Ptni Alloy

Abstract Diabetes has become a universal epidemic in recent years. Herein, the monitoring of glucose in blood is of importance in clinical applications. In this work, PtNi alloy nanoparticles homogeneously dispersed on graphene (PtNi alloy-graphene) was synthesized as a highly effective electrode material for glucose detection. Based on the modified PtNi alloy-graphene/glass carbon (PtNi alloy-graphene/GC) electrode, it is found that the PtNi alloy-graphene/GC electrode exhibited excellent electrocatalytic performance on glucose oxidation. Furthermore, the results from amperometric current–time curve show a good linear range of 0.5–15 mM with the limit of detection of 16 uM (S/N = 3) and a high sensitivity of 24.03 uAmM−1 cm−2. On account of the good selectivity and durability, the modified electrode was successfully applied on glucose detection in blood serum samples.

Nonenzymatic Glucose Biosensor Based on NiNPs/Nafion/Graphene Film for Direct Glucose Determination in Human Serum

NANO ◽  
2018 ◽  
Vol 13 (07) ◽  
pp. 1850075 ◽  
Author(s):  
Parviz Sukhrobov ◽  
Sodik Numonov ◽  
Sanshuang Gao ◽  
Xamxikamar Mamat ◽  
Thomas Wagberg ◽  
...  
Keyword(s):  
Human Serum ◽  
Glucose Oxidation ◽  
Limit Of Detection ◽  
Graphene Film ◽  
High Sensitivity ◽  
Linear Range ◽  
Signal To Noise ◽  
Serum Samples ◽  
Coefficient Of Correlation ◽  
Glucose Determination

This study describes a type of novel nickel nanoparticles (NiNPs) decorated on Nafion-graphene composite film by using the electrochemical deposition method. It was used to fabricate electrochemical biosensors for sensitive nonenzymatic glucose detection. Compared with the Nafion–graphene film and NiNPs-modified glassy carbon electrode (NiNPs-GCE), the NiNPs/Nafion/graphene/GCE showed the best electrocatalytic activity towards glucose oxidation in alkaline medium. The NiNPs/Nafion/graphene/GCE at an applied potential of [Formula: see text]0.55[Formula: see text]V in a linear range of 1–200[Formula: see text][Formula: see text]M presented a high sensitivity of 3437.25[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text] with coefficient of correlation [Formula: see text]; and in a linear range of 200–10[Formula: see text]800[Formula: see text][Formula: see text]M it performed the best sensitivity of 2848.6[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text] with coefficient of correlation [Formula: see text] towards glucose oxidation. For a concentration up to 200[Formula: see text][Formula: see text]M, a linear range was obtained with a limit of detection of 0.6[Formula: see text][Formula: see text]M (signal to noise [Formula: see text] 3) and as much as 10[Formula: see text]800[Formula: see text][Formula: see text]M with a limit of detection of 0.82[Formula: see text][Formula: see text]M (signal to noise [Formula: see text] 3). The time of responses was about 1–1.5[Formula: see text]s with the addition of 0.1–1[Formula: see text]mM glucose. In addition, NiNPs/Nafion/graphene/GCE also has a high anti-interference ability toward common oxidative interfering species, such as uric acid, ascorbic acid and dopamine. More importantly, NiNPs/Nafion/graphene/GCE was successfully used for the determination of glucose concentration in human serum samples in comparison with a local hospital. The NiNPs/Nafion/graphene/GCE exhibited high sensitivity, low working potential, good stability, excellent electrical properties, enhanced selectivity and fast amperometric responses to glucose oxidation. Thus, as a nonenzymatic sensor, it is promising for future glucose determination development.

scholarly journals Copper-nickel oxide nanofilm modified electrode for non-enzymatic determination of glucose

2020 ◽  
Vol 10 (3) ◽  
pp. 245-255
Author(s):  
Mahsa Hasanzadeh ◽  
Zahra Hasanzadeh ◽  
Sakineh Alizadeh ◽  
Mehran Sayadi ◽  
Mojtaba Nasiri Nezhad ◽  
...  
Keyword(s):  
Modified Electrode ◽  
Limit Of Detection ◽  
High Sensitivity ◽  
Stability Loss ◽  
The Novel ◽  
Step Potential ◽  
Enzymatic Determination ◽  
Wide Range ◽  
Naoh Solution

CuxO-NiO nanocomposite film for the non-enzymatic determination of glucose was prepared by the novel modifying method. At first, anodized Cu electrode was kept in a mixture solution of CuSO4, NiSO4 and H2SO4 for 15 minutes. Then, a cathodization process with a step potential of -6 V in a mixture solution of CuSO4 and NiSO4 was initiated, generating formation of porous Cu-Ni film on the bare Cu electrode by electrodeposition assisted by the release of hydrogen bubbles acting as soft templates. Optimized conditions were determined by the experimental design software for electrodeposition process. Afterward, Cu-Ni modified electrode was scanned by cyclic voltammetry (CV) method in NaOH solution to convert Cu and Ni nanoparticles to the nano-scaled CuxO-NiO film. The electrocatalytic behavior of the novel CuxO-NiO film toward glucose oxidation was studied by CV and chronoamperometry (CHA) techniques. The calibration curve of glucose was found linear in a wide range of 0.04–5.76 mM, with a low limit of detection (LOD) of 7.3 µM (S/N = 3) and high sensitivity (1.38 mA mM-1 cm-2). The sensor showed high selectivity against some usual interfering species and high stability (loss of only 6.3 % of its performance over one month). The prepared CuxO-NiO nanofilm based sensor was successfully applied for monitoring glucose in human blood serum and urine samples.

scholarly journals Preparation of Cerium Oxide-MWCNTs Nanocomposite Bulk Modified Carbon Ceramic Electrode: A Sensitive Sensor for Tamoxifen Determination in Human Serum Samples

2021 ◽  
Author(s):  
Sepideh Shafaei ◽  
Elyas Hosseinzadeh ◽  
Gulsah Saydan Kanberoglu ◽  
Balal Khalilzadeh ◽  
Rahim Mohammad-Rezaei
Keyword(s):  
Cerium Oxide ◽  
Limit Of Detection ◽  
Low Cost ◽  
High Electron ◽  
Range Limit ◽  
Serum Samples ◽  
Important Species ◽  
Carbon Ceramic Electrode ◽  
Carbon Ceramic

Abstract In this study, cerium oxide and multi-walled carbon nanotubes nanocomposite was incorporated into the carbon ceramic electrode (CeO2-MWCNTs/CCE) as a renewable electrode for the electrocatalytic purposes. To demonstrate capability of the fabricated electrode, determination of Tamoxifen as an important anticancer drug with differential pulse voltammetry technique was evaluated. Linear range, limit of detection and sensitivity of the developed sensor were found to be 0.2-40 nM, 0.132 nM and 1.478 µA nM-1 cm-2, respectively. Ease of production, low cost and high electron transfer rate of CeO2-MWCNTs/CCE promise it as a novel electro-analytical tool for determination of important species in real samples.

Gas-chromatographic determination of 5-fluorocytosine in human serum.

1976 ◽  
Vol 22 (6) ◽  
pp. 772-776 ◽  
Author(s):  
S A Harding ◽  
G F Johnson ◽  
H M Solomon
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Mean Value ◽  
Normal Serum ◽  
Trimethylsilyl Derivative ◽  
Serum Samples ◽  
Gas Chromatographic Method

Abstract We describe a sensitive and precise gas-chromatographic method, in which cytosine is used as the internal standard, for determination of an antifungal agent, 5-fluorocytosine, in serum. The trimethylsilyl derivative of this drug is well separated from the internal standard and from normal serum constituents. Amphotericin B does not interfere with the determination of 5-fluorocytosine. The lower limit of detection for 5-fluorocytosine is 1 mg/liter when 200 mul of serum is analyzed. Within-run precision (CV), established by analysis of 10 replicates, was 4.5% at a concentration of 19.9 mg/liter. Twenty-five serum samples were analyzed for 5-fluorocytosine by a microbiological assay and by the gas-chromatographic method. Mean value observed with the bioassay was 78.5 mg/liter and with our procedure was 69.4 mg/liter. When values for our assay were regressed against values for the bioassay, slope of the least-squares line was 0.85, intercept was 2.7 mg/liter, and r was 0.93.

Biological Conjugate between Antibody and ZnS Nanoparticles as Probe for Atomic Absorption Spectrophotometry Determination of Estriol

2014 ◽  
Vol 556-562 ◽  
pp. 64-66
Author(s):  
Chun Yan Zhang ◽  
Chuan Tao Wang ◽  
Shu Hao Wang ◽  
Ling Yun Du
Keyword(s):  
Atomic Absorption ◽  
Limit Of Detection ◽  
Water Solution ◽  
Semiconductor Nanocrystals ◽  
Atomic Absorption Spectrophotometry ◽  
Serum Samples ◽  
Absorption Spectrophotometry ◽  
Primary Materials ◽  
Good Agreement

ZnS semiconductor nanocrystals (NCs) were prepared by ways from primary materials of ZnCl2 and Na2S in water solution. Using the synthesized ZnS NCs, a polyclonal antibody-based ZnS-labelled immunosorbent assay for the determination of estriol (E3) was developed with atomic absorption spectrophotometry (AAS) as a detector. An immunoaffinity column was applied to testify conjugation between antibody and ZnS NCs. The linear range for determination of estriol is 40.0~600.0 ng.mL-1, and the limit of detection (LOD) is 10.0 ng.mL-1. Some serum samples have been analyzed with satisfactory results which are in good agreement with those obtained using ELISA. This work suggests the potential application of NCs as biological probes and AAS as detector in nonisotopic immunoassay.

scholarly journals Determination of cyanide in bamboo shoots by microdiffusion combined with ion chromatography–pulsed amperometric detection

2018 ◽  
Vol 5 (4) ◽  
pp. 172128 ◽  
Author(s):  
Ming Ding ◽  
Kailiang Wang
Keyword(s):  
Ion Chromatography ◽  
Limit Of Detection ◽  
Correlation Coefficients ◽  
Amperometric Detection ◽  
High Sensitivity ◽  
Practical Method ◽  
Pulsed Amperometric Detection ◽  
Bamboo Shoots ◽  
Relative Standard

A practical method for the determination of cyanide in bamboo shoots has been developed using microdiffusion preparation integrated with ion chromatography–pulsed amperometric detection (IC-PAD). Cyanide was released from bamboo shoots after Conway cell microdiffusion, and then analysed by IC-PAD. In comparison with the previously reported methods, derivatization and ion-pairing agent addition were not required in this proposed microdiffusion combined with IC-PAD method. The microdiffusion parameters were optimized including hydrolysis systems, temperature, time, and so on. Under the optimum conditions, the linear range of the calibration curve for cyanide was 0.2–200.0 µg kg −1 with satisfactory correlation coefficients of 0.9996 and the limit of detection was 0.2 µg kg −1 ( S/N  = 3). The spiked recovery range was from 92.8 to 98.6%. The intra-day and inter-day relative standard deviations of cyanide were 2.7–14.9% and 3.0–18.3%, respectively. This method was proved to be convenient in operation with high sensitivity, precision and accuracy, and was successfully applied in the determination of cyanide in bamboo shoot samples.

Single- and coupled-enzyme nylon-tube reactors for plasma glucose determination with glucose oxidase and aldehyde dehydrogenase.

1980 ◽  
Vol 26 (12) ◽  
pp. 1652-1655 ◽  
Author(s):  
W Hinsch ◽  
A Antonijewić ◽  
P V Sundaram
Keyword(s):  
Glucose Oxidase ◽  
Aldehyde Dehydrogenase ◽  
Plasma Glucose ◽  
Continuous Flow ◽  
Flow System ◽  
Low Cost ◽  
Immobilized Enzymes ◽  
Glucose Determination ◽  
Nylon Tube

Abstract We describe routine methods for determining glucose in plasma with use of aldehyde dehydrogenase or glucose oxidase-aldehyde dehydrogenase immobilized in a nylon tube that is integrated into a continuous-flow system. Although the coupled-enzyme nylon-tube reactors require the presence of a third enzyme, catalase, in solution, the kinetics are not so complicated as to preclude reliable routine determination of glucose at very low cost. Precision is good, and results correlate well with those by the method involving glucose oxidase in solution. More than 3000 tests may be carried out with one reactor. The immobilized enzymes are stable for several months at 4 degrees C when not in use.

scholarly journals Rapid and Selective Determination of Folate Receptor α with Sensitive Resonance Rayleigh Scattering Signal

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Liping Wu ◽  
Yue Liu ◽  
Rong Huang ◽  
Huawen Zhao ◽  
Weiqun Shu
Keyword(s):  
Rayleigh Scattering ◽  
Folate Receptor ◽  
Specific Interaction ◽  
High Sensitivity ◽  
Resonance Rayleigh Scattering ◽  
Serum Samples ◽  
Au Nps ◽  
Selective Determination ◽  
Limit Of Determination

A rapid, simple, and novel method for folate receptor α (FRα) determination is reported here. A probe of gold nanoparticles (Au NPs) modified with anti-FRα antibody was synthesized under the optimized conditions first. The antibody-modified Au NPs would aggregate when FRα was added to the probe for the specific interaction between antibody and antigen, resulting in the enhancement of resonance Rayleigh scattering (RRS) intensity. There is a linear relationship between the change of RRS intensity (ΔIRRS) and the concentration of FRα, with the detecting range of 0.50–37.50 ng·mL−1 and the limit of determination of 0.05 ng·mL−1. The determination of FRα in serum samples was realized with the advantages of high selectivity, high sensitivity, and easy operation.

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