Selective Detection Of Glucose Research Articles

Hydrothermal Growth of Molybdenum Disulfide Composited with Electrodeposited Gold and Its Photoelectrochemical Properties

Recently, molybdenum disulfide (MoS2) has received remarkably attention due to its excellent optical and electrical properties. Notably, the narrow bandgap of transition metal dichalcogenide (TMDC) MoS2 makes it a promising candidate for photoelectrochemical (PEC) applications. Direct growth of MoS2 via hydrothermal synthesize offers improved electrical conductivity between the MoS2 and the substrate, which allows for better application and electrical signal readings as a result of elevated electron transfer routs compared with drop-casted MoS2. Here, we studied the effect of hydrothermal growth time of MoS2 nanosheets on the morphology evolution as well as the PEC sensing properties. The time evolution studies conducted in the range of 2-10 hours. We used surface characterization method such as field emission scanning electron microscopy and analytical techniques such as chronoamperometry, cyclic voltammetry and electrochemical impedance spectroscopy to study the morphology evolution and PEC sensing properties. Our results revealed that the direct growth of MoS2 not only enhances the sensor signal but also encourages nanocomposites of MoS2 with gold- a key to simultaneouse amplification of the optical and electrical properties. Effect of applied bias potential in the range of 0.45-0.85 V vs. Ag/AgCl on photocurrent response was also investigated. We further used 3D COMSOL simulation to assess the effect of gold thickness on the electric field intensity of the sensing MoS2/Au electrodes. Eventually, we studied sensitive and selective detection of glucose as an important molecule in the human body. Our developed MoS2/Au composite demonstrated a very low limit of detection (1.3 nM) and excellent sensitivity for non-enzymatic PEC sensing of glucose. Moreover, the selectivity of the fabricated sensor were examined by monitoring the photocurrent responses towards different interfering agents under illumination.

Bimetallic PtAu alloy nanomaterials for nonenzymatic selective glucose sensing at low potential

Electrochemical nonenzymatic glucose sensing meets the challenge of excellent selectivity and the minimum poisoning effect of the electrode. Bimetallic alloys based on Pt have distinct synergistic characteristics and offer remarkable anti-poisoning capability and electrocatalytic performance for sensitive and selective glucose sensing at low potential. Bimetallic PtAu alloy nanomaterials loaded into nanocarbon carrier (PtAu/C) were successfully fabricated. The morphology and structure of PtAu bimetallic alloy were observed. The voltammetric response of the PtAu/C modified electrodes towards glucose oxidation in NaOH revealed significant enhanced compared with Pt/C or Au/C. PtAu (1:1)/C with 0.4 wt% content of Pt was used for selective glucose detection at a low potential of −0.33 V (vs. SCE). Interfering substances revealed inert and ignorable analytical influence on glucose detection. Furthermore, DPV was applied for sensitive determination of glucose. A linear relationship was found between peak current and glucose concentration within the range of 0.01–10 mM with the limit of detection (LOD) of 3 μM. Validation in human serum samples indicated that the PtAu (1:1)/C (0.4 wt% Pt) modified electrode accurately detected glucose. The PtAu bimetallic alloy exhibited a bright prospect for the glucose analysis of real samples.

Synthesis of blue fluorescent carbon dotsfor sensitive and selective detection of glucose in biological samples

This Article describes a technique for the preparation of blue fluorescent carbon dots (CDs) showing fluorescence emission at 450nm. CDs were prepared using ultra-sonication technique using citric acid and glycerol as precursors. Since glucose quenches the fluorescence of CDs, depending upon this fact, a fluorescent sensor for glucose determination has been established. Under optimized conditions, linear response in therange of 0.1-100µM was obtained for glucose concentration. Limit of detection is found to be 0.08µM. This method was promisingly used for the glucose determination in serum albumin samples and urine samples from different human beings.

Chitosan–Fe3O4 nanoparticle enzymatic electrodes on paper as an efficient assay for glucose and uric acid detection in biological fluids

In this study, two important biomarkers, namely glucose and uric acid, were detected in different biological fluids using a highly sensitive and selective chitosan-/nano-based electrochemical microfluidic paper-based analytical device (µPAD). A graphite/chitosan/polyethylene glycol (PEG) mixture was used as bare working electrode and counter electrode with silver ink being used as quasi-reference electrode. Graphene, multiwall carbon nanotubes, and Fe3O4 nanoparticles were used to improve sensitivity as well as selectivity of the working electrodes. The developed chitosan-/nano-based microfluidic analytical system showed apparent redox peaks, and all the three types of nanomaterials improved the performance of the bare graphite/chitosan/PEG electrode with the Fe3O4-modified electrode exhibiting the sharpest signals with the highest selectivity. The linear ranges of glucose and uric acid were 0.01–30 mM and 0.05–15 mM, respectively, where the limits of detection (LOD) were 5 µM and 20 µM for glucose and uric acid, respectively. In comparison with most of previous data reported on μPADs and due to high surface area/volume ratio of NPs and faster electron transfer promoted by chitosan and NPs, the better LODs were found in the current study. The fast, efficient, and low-cost µPADs were successfully applied to highly sensitive and selective detection of glucose and uric acid in serum and urine samples and noninvasive glucose detection in tear samples.

Hybrids of Nickel-histidine Functionalized Graphene Quantum Dots: Fabrication and Non-enzymatic Glucose Sensing

In this work, a method of in-situ recombination of Ni2+ with histidine functionalized graphene quantum dots (His-GQDs) was constructed a three-dimensional network porous structure. The collected precipitate complex precursor was oxidized and the NiO-His-GODs were obtained. The NiO-His-GQDs compound was subjected to high-temperature thermal reduction by inert gas to form Ni-His-GQDs. On the one hand, the intimate contact between Ni nanoparticles and His-GQD greatly shortens the gap between the two complexes, resulting in faster electron migration speed; On the other hand, the conductive (Ni)/semiconductor (His-GQDs) catalytic interface can produce Stokes diode-like structures, accelerate the migration rate of holes carriers in the semiconductor, and exhibit good electrocatalytic activity. A Ni-His-GQDs modified electrode as non-enzymatic glucose electrochemical sensor was shown good electrocatalytic activity and anti-interference property. The concentration of glucose was detected by amperometric analysis, and showed a good linear relation in the concentration range of 5.0 × 10-6∼2.0 × 10-3 M. The detection limit (S/N = 3) is 1.7 × 10−6 M. In addition, interference of sodium chloride (NaCl), uric acid (UA), dopamine (DA) and ascorbic acid (AA) was less than 5.0 % in the same conditions indicating that the hybrids modified electrode sensor could be used for the sensitive and selective detection of glucose.

Colorimetric biosensing of glucose in human serum based on the intrinsic oxidase activity of hollow MnO2 nanoparticles

Hollow MnO2 nanoparticles with excellent oxidase-like activity for the sensitive and selective detection of glucose in human serum.

Nickel oxide decorated MoS2 nanosheet-based non-enzymatic sensor for the selective detection of glucose.

Understanding blood glucose levels in our body can be a key part in identifying and diagnosing prediabetes. Herein, nickel oxide (NiO) decorated molybdenum disulfide (MoS2) nanosheets have been synthesized via a hydrothermal process to develop a non-enzymatic sensor for the detection of glucose. The surface morphology of the NiO/MoS2 nanocomposite was comprehensively investigated by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analysis. The electro-catalytic activity of the as-prepared NiO/MoS2 nanocomposite towards glucose oxidation was investigated by cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and amperometry in 0.1 M NaOH. The NiO/MoS2 nanocomposite-based sensor showed outstanding electrocatalytic activity for the direct electro-oxidation of glucose due to it having more catalytic active sites, good conductivity, excellent electron transport and high specific surface area. Meanwhile, the NiO/MoS2 modified glassy carbon electrode (GCE) showed a linear range of glucose detection from 0.01 to 10 mM by amperometry at 0.55 V. The effect of other common interferent molecules on the electrode response was also tested using alanine, l-cysteine, fructose, hydrogen peroxide, lactose, uric acid, dopamine and ascorbic acid. These molecules did not interfere in the detection of glucose. Moreover, this NiO/MoS2/GCE sensor offered rapid response (2 s) and a wide linear range with a detection limit of 1.62 μM for glucose. The reproducibility, repeatability and stability of the sensor were also evaluated. The real application of the sensor was tested in a blood serum sample in the absence and presence of spiked glucose and its recovery values (96.1 to 99.8%) indicated that this method can be successfully applied to detect glucose in real samples.

Enzymatic Preparation of Plasmonic-Fluorescent Quantum Dot-Gold Hybrid Nanoprobes for Sensitive Detection of Glucose and Alkaline Phosphatase and Dual-Modality Cell Imaging

Herein, we develop a route to prepare bifunctional plasmonic-fluorescent quantum dot-gold (QD-Au) hybrid nanoprobes by use of enzymatic reactions. Two bioenzymes, glucose oxidase (GOx) and alkaline phosphatase (ALP) were chosen for the enzymatic preparation of core-satellite or core-shell type CdSe/ZnS@Au hybrid nanostructures. The enzymatic products, H2O2 and l-ascorbic acid, of the two enzymes were exploited as mild reducing agents for controlled Au deposition on QD surfaces. The polymer multilayers by layer-by-layer assembly were used to adjust the separation between QD core and plasmonic Au, which can effectively reduce the quenching effect of the Au on QDs. The as-prepared QD@Au hybrid nanostructures are excellent dual-modality imaging nanoprobes, and can be used for fluorescence and dark-field scattering dual-imaging of MCF-7 cells. More importantly, the two enzymatic reaction systems can be explored for sensitive and selective detection of glucose and alkaline phosphatase, respectively, by monitoring the fluorescence spectra change of QD@Au hybrid nanoparticles, which is very useful for the glucose- and ALP-related disease diagnosis.

Plasma‐functionalized Highly Aligned CNT‐based Biosensor for Point of Care Determination of Glucose in Human Blood Plasma

AbstractIn this study, a new method for modification of vertically aligned carbon nanotube arrays (VACNTs) for selective detection of glucose was developed. VACNTs were grown by chemical vapor deposition method on a silicon substrate deposited with alumina as a buffer layer and iron as a catalyst using radio frequency (RF) sputtering and electron beam evaporation, respectively. The surface of the electrode was modified with electrodeposition of polyaniline (PANI) followed by covalent attachment of glucose oxidase (GOx). The electrode was characterized using field emission scanning electron microscopy (FESEM), micro‐Raman spectroscopy, and attenuated total reflectance Fourier transform infrared spectrometer (ATR‐FTIR) techniques. Cyclic voltammetry and differential pulse voltammetry were used to investigate the electrochemical behavior of the electrode. The fabricated electrode was successfully employed as a point‐of‐care (POC) biosensor for the detection of glucose in human blood plasma. The detection limit was 1.1 μM, and the sensitivity was 620 μA mM−1 cm−2 at the linear range of 2–426 μM.

Co3O4 nanoparticles supported mesoporous carbon framework interface for glucose biosensing

The present work reports the preparation of advanced functional nanostructures based on cobalt oxide supported mesoporous carbon framework (Co3O4@MCF) for electrochemical biosensing. Co3O4@MCF was synthesized by simple hythrothermal & pyrolysis method and further characterized by various microscopic and spectroscopic techniques. The transmission electron microscopic (TEM) images show the lattice fringes of crystalline Co3O4 with interlayer spacing of 0.24 nm. The characteristic 311 plane in X-ray diffraction (XRD) studies further confirmed the presence of crystalline Co3O4 on carbon frameworks. Reflection of prominent A1g peak along with D and G band in raman spectra confirmed the successful fabrication of Co3O4@MCF nanocomposite. Prepared Co3O4@MCF manifested great porosity, good biocompatibility and large surface area which allowed effective immobilization of glucose oxidase (GOx) onto its surface using chitosan (Chi) as a binder. Thus, a nanocomposite (Co3O4@MCF-Chi-GOx) modified glassy carbon electrode (GCE) was fabricated for highly selective detection of glucose using amperometry and cyclic voltammetry. The Co3O4@MCF-Chi-GOx/GCE electrode exhibited excellent biosensing performance for glucose monitoring with detection limit of (LOD) of 107.70 μM and reproducibility of 4.7% RSD. Moreover, the biosensor holds great promise for its effective implications in point-of-care diagnostics of small biomolecules.

An alternative electron transfer process for selective detection of glucose in blood serum

Here, we demonstrate efficient electrochemical detection of glucose in blood serum using CdS nanoribbons coated indium Tin Oxide (ITO) electrode. Main appeal of this work is to establish an alternative electron transfer (AET) process by dissolving the glucose oxidase (GOX) enzyme in the electrolyte instead of direct immobilization on the electrode’s surface to demonstrate better performance of glucose sensing. In this context, we developed an experimental strategy through amperometric detection of hydrogen peroxide (H2O2) which is an intermediate reaction product of glucose oxidation by GOX present in the buffer solution. Therefore, we separately performed electrochemical detection of H2O2 by CdS nanoribbons in buffer solution followed by glucose detection with the same electrode by dissolving GOX in the buffer solution. The linear range of amperometric current measured with the same concentration of both H2O2 and glucose overlaps with each other which clearly proves that electrocatalytic reduction of both the analytes occur at the same rate on the CdS surface. Our studies reveal that dissolved GOX in buffer solution have a better performance than the GOX immobilized electrode. Furthermore, chronoamperometric detection of glucose in actual blood serum sample was performed and our results show even better performance than the commercially available glucometer.

In Situ Formation of a 3D Amorphous Cobalt‐ Borate Nanoarray: An Efficient Non‐Noble Metal Catalytic Electrode for Non‐Enzyme Glucose Detection

AbstractIt is highly desirable to design enzyme‐free nanoarray architecture as an efficient three‐dimensional (3D) catalyst electrode for sensitive and selective detection of glucose. In this communication, we report that in situ electrochemical development of an amorphous cobalt‐borate nanoarray supported on carbon cloth (Co–Bi /CC) as a durable and efficient 3D nanoarray electrocatalyst for glucose detection. As a glucose sensor, Co−Bi/CC electrode shows a fast amperometric response toward glucose, a detection limit of 0.042 μM (S/N=3), a response sensitivity of 4191.7 μA mM−1 cm−2. Importantly, it also demonstrates favourable reproducibility and long‐term stability.

Co-MOF nanosheet array: A high-performance electrochemical sensor for non-enzymatic glucose detection

It is important to construct and develop non-noble-metal nanoarray architecture for sensitive and selective detection of glucose. In this paper, we testify the hydrothermal synthesis of Co-MOF nanosheet array on nickel foam from aqueous Co2+ and terephthalic acid. The resulting Co-MOF array on Ni foam (Co-MOF/NF) exhibits strong activity for glucose oxidation electrocatalysis in alkaline media. As a promising enzymatic-free sensing, the speedy amperometric response of < 5 s, high sensitivity of 10,886 μA mM−1 cm-2 and low detection limit of 1.3 nM (signal/noise = 3) are obtained in the Co-MOF/NF. Our study shows that the material possesses long-time stability and great reproducibility and may be used for the glucose detection in human blood serum and fruit juice.

Direct growth of ternary copper nickel cobalt oxide nanowires as binder-free electrode on carbon cloth for nonenzymatic glucose sensing

A new binder free electrode based on ternary copper nickel cobalt oxide nanowires grown on the carbon cloth (CuNiCoO4 NWs@ carbon cloth) was prepared and characterized by field emission scanning electron microscopy (FE-SEM), x-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX), and cyclic voltammetry (CV). The prepared electrocatalyst was directly used for electrochemical sensing of glucose without using enzyme. The effect of different parameters such as potential scan rate, switching potential, and glucose concentration on the electrochemical oxidation of glucose was investigated. The results showed that such an electrode presents excellent catalytic activity toward the oxidation of glucose in aqueous alkaline solution. Under optimum conditions, the potential application of the electrode was evaluated by applying it to the analytical determination of glucose concentration. The results revealed that the electrocatalytic current increased linearly with the glucose concentration in the range from 0.02 to 1.4 mM with a low detection limit of 6.5 μM and good sensitivity of as high as 1782 μA mM−1 cm−2. Selectivity investigations demonstrate that the CuNiCoO4 NWs@CC electrode could be used for selective detection of glucose in the presence of interfering species. Real sample analysis shows reasonable RSD values implying negligible matrix effect in determination of glucose in human serum samples.

IRMOF-3: A fluorescent nanoscale metal organic frameworks for selective sensing of glucose and Fe (III) ions without any modification

The amine functionalized isoreticular metal-organic framework-3 (IRMOF-3) is synthesized by hydrothermal method. Till now, it's widely used in the area of gas separation, adsorption, and catalysis due to large surface area, structural stability, and tunability. Here, we have reported the use of fluorescent nanoscale IRMOF-3 for highly selective detection of glucose as well as Fe3+ ions without any modification. This is due to NH2 and COOH groups are present on the surface of IRMOF-3 to bind cis-diols of the glucose molecule via host-guest interaction, and Fe3+ ions via ligand to metal charge transfer. The Synthesized IRMOF-3 has average diameter of 160 ± 20 nm and interestingly possess deep blue fluorescent emission spectra at 460 nm with quantum yield 17.3%. Using fluorometric assay, the limit of detection (LOD) of glucose and Fe3+ ions was found to be 0.56 μM and 4.2 nM respectively. More importantly, the synthesized IRMOF-3 is also utilized for detection of glucose and Fe3+ ions in bio-environmental samples.

Development of mini-spectrophotometer for determination of plasma glucose

This work demonstrates a novel compact spectrophotometer, “Mini-spectrophotometer”, designed for plasma glucose detection. Unlike conventional spectrophotometer, a light source of the mini spectrophotometer is replaced by a light-emitting diode (LED), and a fabricated polymer-based microwell is used as a cuvette. To validate the downsizing spectrophotometer prototype, the efficiency and reliability for glucose determination are investigated. Using a certain light intensified from LED, the within-run precision of mini-spectrophotometer is found to be 3.9–8.4% while the between-run precision is 6.7–10.8%. The linearity for the quantification of glucose was up to 500 mg dL−1 and the recovery 99.1 ± 3.4% is obtained. The sensitive and selective detection of glucose has been observed; with limit of detection (LOD) of 13.5 mg dL−1 and limit of quantification (LOQ) of 46.2 mg dL−1, respectively. Hemoglobin and triglyceride at high concentration slightly interferes with the proposed instrument. From comparative studies, there are no significant differences between the glucose concentration measured by mini-spectrophotometer and Shimadzu (r2 = 0.9862) or CECIL spectrophotometer (r2 = 0.9853). Using Passing-Bablok regression analysis, the results obtained from mini-spectrophotometer are in close agreement with the two conventional spectrophotometers. Furthermore, using microwell, the sample volume and reagent used in the process can be reduced. The in-house developed mini-spectrophotometer is capable of detecting plasma glucose while maintaining a compact system, demonstrating the potential of high performance, cost-effective, and portable spectrophotometer for clinical chemistry analysis in small routine, research, and teaching medical laboratory technologist.

N-doped graphene-carbon nanotube hybrid networks attaching with gold nanoparticles for glucose non-enzymatic sensor

Herein, we successfully developed a novel three dimensional (3D) opened networks based on nitrogen doped graphene‑carbon nanotubes attaching with gold nanoparticles (N-GR-CNTs/AuNPs) to apply for non-enzymatic glucose determination. It was demonstrated that the N-GR-CNTs/AuNPs modified electrode exhibited good behavior for glucose detection with a long linear range of 2 μM to 19.6 mM, high sensitivity of 0.9824 μA·mM−1·cm−2, low detection limit of 500 nM, and negligible interference effect. The high performance of the N-GR-CNTs/AuNPs based sensor was assumed due to the outstanding catalytic activity of AuNPs well dispersing on N-GR-CNTs networks, which exhibited as a perfect supporting scaffold due to the enhanced electrical conductivity and large surface area. The obtained results indicated that the N-GR-CNTs/AuNPs hybrid is highly promising for sensitive and selective detection of glucose in sensor application.

Molecular Imprinting Polymers Based on Boric Acid-Modified CdTe QDs for Sensitive Detection of Glucose

In this study, a novel imprinted polymer based on 3-aminophenylboronic acid (APBA)-functionalized CdTe quantum dots (QDs) was synthesized and used to sensitively and selectively detect glucose. In the process of synthesis, the boronic acid in the APBA could combine covalently with vicinal diol compounds, directing imprinting process, and the APBA-modified CdTe QDs were used as the solid supports. By this method, the prepared molecular imprinting polymers (MIPs)-APBA/CdTe QDs show high selectivity, high sensitivity and good stability. Under optimal conditions, a linear relationship was obtained covering the linear range of 0–1.5[Formula: see text]mmol/L with a correlation coefficient of 0.99833 and a high imprinting factor about 5.71. Furthermore, the prepared MIPs-APBA/CdTe QDs were successfully applied to detect glucose in human serum samples. This work provides a new way to synthesize an excellent stability and efficient imprinted polymer based on CdTe QDs for convenient, fast and highly selective detection of glucose.

One step synthesis of AuNPs@MoS2-QDs composite as a robust peroxidase- mimetic for instant unaided eye detection of glucose in serum, saliva and tear

A graphene analogous of transition metal dichalcogenides, mainly molybdenum disulfide (MoS2), have recently attracted wide attention due to its catalytic and electrical properties. Herein, we report a simple one step synthesis of gold nanoparticles (AuNPs) decorated over MoS2 quantum dots (AuNPs@MoS2-QDs) as a robust peroxidase- mimetic material. The AuNPs@MoS2-QDs composite catalyzes the peroxidase substrate of 3, 3′, 5,5′-tetramethylbenzidine (TMB) oxidation in the presence of H2O2 to produce a bluish-green colored product. The peroxidase mimetic behavior of AuNPs@MoS2-QDs composite complies with the steady state kinetics and is stable in harsh conditions such as high or low temperature and pH. The developed composite system has been used for sensitive and selective detection of glucose. The developed biosensor shows an excellent detection in dynamic ranges from 1 to 400 μM (R2∼0.996) with the detection limit of 0.068 μM in PBS buffer solution. Low Km value (0.06 mM) of AuNPs@MoS2-QDs has shown strong binding affinity towards substrates along with high values of Vmax (10.6 × 10−6 Ms−1) indicating greater catalytic reaction rate. Further the biosensor is developed as a portable test kit for detection of glucose in biological fluids like serum, tear and saliva utilizing agarose hydrogel as a visual detection platform. Our portable sensing kit shows an excellent response for detection of glucose in real samples compared to the conventional methods.

Paper-based fluorescent sensor via aggregation induced emission fluorogen for facile and sensitive visual detection of hydrogen peroxide and glucose

Hydrogen peroxide (H2O2), an important reactive oxygen species (ROS), is related to the oxidative stress in organisms, and plays important roles in a variety of cellular activities as well. So it is of crucial importance to develop sensitive and accurate sensing strategies to detect H2O2 in biological systems. Herein, by taking advantage of the unique emission characteristics of aggregation induced emission (AIE) fluorogens, we proposed a non-enzymatic fluorescence platform for facile and sensitive detection of H2O2, both in solution state using fluorescence spectrometer and on paper-based sensor via visual inspection. Through the reaction between L-cysteine and H2O2, the fluorescence of TPE-M-L, an AIE fluorogen formed between maleimide-functionalized tetraphenylethene (TPE-M) and L-cysteine, is quenched, and highly sensitive non-enzymatic H2O2 assay is readily carried out. The limit of detection (LOD) of 10nM in solution state and 2.5μM on paper-based sensor were obtained for H2O2 detection, which were superior or comparable to those previously reported in literature. Moreover, by integrating glucose oxidase with the AIE fluorogen of TPE-M-L, highly sensitive and selective glucose detection was also conveniently achieved both in solution state and on paper-based sensor by the as-proposed strategy, with the LODs of 50nM in solution state and 10μM via visual observation, much better than those obtained by other fluorescence methods. The as-proposed sensing strategy was also successfully applied to assay glucose in human serum samples. Therefore, the paper-based fluorescence sensor exhibits the advantages of simple fabrication, high sensitivity and portability, and has great potential to be applied in on-site assay of H2O2 and glucose in real samples.