Sensitive Glucose Sensor Research Articles

Insulin-dependent glucose consumption dynamics in 3D primary human liver cultures measured by a sensitive and specific glucose sensor with nanoliter input volume.

The liver plays a central role in glucose homeostasis and hepatic insulin resistance constitutes a key feature of type 2 diabetes. However, platforms that accurately mimic human hepatic glucose disposition and allow for rapid and scalable quantification of glucose consumption dynamics are lacking. Here, we developed and optimized a colorimetric glucose assay based on the glucose oxidase-peroxidase system and demonstrate that the system can monitor glucose consumption in 3D primary human liver cell cultures over multiple days. The system was highly sensitive (limit of detection of 3.5µM) and exceptionally accurate (R2 =0.999) while requiring only nanoliter input volumes (250nL), enabling longitudinal profiling of individual liver microtissues. By utilizing a novel polymer, off-stoichiometric thiol-ene (OSTE), and click-chemistry based on thiol-Michael additions, we furthermore show that the assay can be covalently bound to custom-build chips, facilitating the integration of the sensor into microfluidic devices. Using this system, we find that glucose uptake of our 3D human liver cultures closely resembles human hepatic glucose uptake in vivo as measured by euglycemic-hyperinsulinemic clamp. By comparing isogenic insulin-resistant and insulin-sensitive liver cultures we furthermore show that insulin and extracellular glucose levels account for 55% and 45% of hepatic glucose consumption, respectively. In conclusion, the presented data show that the integration of accurate and scalable nanoliter glucose sensors with physiologically relevant organotypic human liver models enables longitudinal profiling of hepatic glucose consumption dynamics that will facilitate studies into the biology and pathobiology of glycemic control, as well as antidiabetic drug screening.

A high sensitive glucose sensor based on Ag nanodendrites/Cu mesh substrate via surface-enhanced Raman spectroscopy and electrochemical analysis

A high sensitive micro/nano-structured glucose sensor via Surface Enhanced Raman Spectroscopy (SERS) detection and electrochemical analysis was developed in this work. Ag nanodendrites/Cu mesh substrate were prepared through facile electrochemical deposition method, which exhibited high SERS sensitivity and electrocatalytic activity. By SERS measurements, glucose can be detected as low as 0.005 mM and exhibit a good linear relationship between concentrations (0.5–5 mM) and the SERS intensities. Moreover, glucose in human urine with different concentrations were successfully detected by the substates. By electrochemical method, the conductivity was firstly tested by CV and ESI tests. Amperometric responses of 0.5 mM glucose were compared with Cu mesh electrode, and the Ag nanodendrites/Cu mesh electrode showed higher electrochemical detection sensitivity. Results revealed the Ag nanodendrites/Cu mesh substrate can be used as glucose sensor with high detection sensitivity, reproducibility, selectivity and practicability, which has great potential in noninvasive medical diagnosis in further works.

In-situ growth of porous CoTe2 nanosheets array on 3D nickel foam for highly sensitive binder-free non-enzymatic glucose sensor

The combination of transition-metals with chalcogens provide a platform for developing highly sensitive and stable electro-catalyst materials possessing excellent electrochemical features regarding glucose oxidation. The growth of porous cobalt telluride (CoTe2) nanosheets (NSs) on a three-dimension (3D) nickel foam (NF) scaffold via anion-exchange transformation is achieved by employing low temperature scalable hydrothermal process. Being an active catalyst material for glucose detection, the CoTe2 NSs/NF electrode demonstrates an ultra-prompt response time of 0.1 s, boosting sensitivity of 168000 μA mM−1 cm−2, low limit of detection of 0.59 μM along with excellent anti-interference ability and favorable stability. Besides, the effective electrochemical performance of sensing electrode is recognized with respect to the glucose detection in real human blood serum. Overall, this material guarantees free-standing 3D architecture, interconnected porous NSs morphology, large specific surface area, high conductivity, and appealing electro-catalytic activity. Therefore, the porous CoTe2 NSs/NF binder-free electrode has a great application prospect as a promising biomimetic catalyst material for highly sensitive and efficient non-enzymatic glucose sensor.

Sensitive colorimetric glucose sensor by iron-based nanozymes with controllable Fe valence.

The proportion of Fe2+ and Fe3+ in Fe-based nanozymes is a key point in determining their catalytic activity. However, it is hard to adjust the Fe2+/Fe3+ ratio in nanozyme systems to achieve the best catalytic performance. In this work, we successfully regulate Fe2+/Fe3+ ratios in a wide range of 0.81-1.45 based on a novel porous platform of Fe doped silica hollow spheres. The homogeneous distribution and stable fixation of Fe components in Fe doped silica hollow spheres facilitate the valence regulation of Fe in the reduction heating in H2/Ar. When the Fe doped spheres (FeOx@SHSs) were used as nanozymes, different Fe2+/Fe3+ ratios have shown to influence the peroxidase-like catalytic activity greatly. The highest activity at the ratio of 1.41 should be due to the combined effects of the accelerated reaction rate by Fe2+ and the enhanced catalytic cycle efficiency by Fe3+. The FeOx@SHSs-based nanozyme is further applied to construct a facile colorimetric biosensing system, which exhibited extremely sensitive determination of glucose. This work presents an effective platform for controlling Fe valences and optimizing the peroxidase-like activity for catalytic processes or sensing systems.

Highly sensitive glucose sensor based on hierarchical CuO

The fabrication of high performance CuO based glucose sensors remains a great challenge due to the “trade-off effect” between sensitivity and linear range. In this study, a hierarchical CuO nanostructure with a great number of firecracker-shaped nanorods along the ligament and three-dimensional interconnected nanoporous is obtained by dealloying and post oxidation process of Al-33.3 wt% Cu eutectic alloy ribbons. Because of the precise structural design, not only the number of active sites for glucose electro-oxidation is significantly increased but also the glucose diffusion under high concentration is greatly accelerated, leading to a high sensitivity of 1.18 mA cm−2 mM−1 and a wider linear range up to 5.53 mM for glucose detection. This work provides a potential approach to design hierarchical nanostructure for other metal oxides with desirable properties for electrocatalytic applications.

Electrochemically Activated Conductive Ni-Based MOFs for Non-enzymatic Sensors Toward Long-Term Glucose Monitoring.

Continuous intensive monitoring of glucose is one of the most important approaches in recovering the quality of life of diabetic patients. One challenge for electrochemical enzymatic glucose sensors is their short lifespan for continuous glucose monitoring. Therefore, it is of great significance to develop non-enzymatic glucose sensors as an alternative approach for long-term glucose monitoring. This study presented a highly sensitive and selective electrochemical non-enzymatic glucose sensor using the electrochemically activated conductive Ni3(2,3,6,7,10,11-hexaiminotriphenylene)2 MOFs as sensing materials. The morphology and structure of the MOFs were investigated by scanning SEM and FTIR, respectively. The performance of the activated electrode toward the electrooxidation of glucose in alkaline solution was evaluated with cyclic voltammetry technology in the potential range from 0.2 V to 0.6 V. The electrochemical activated Ni-MOFs exhibited obvious anodic (0.46 V) and cathodic peaks (0.37 V) in the 0.1 M NaOH solution due to the Ni(II)/Ni(III) transfer. A linear relationship between the glucose concentrations (ranging from 0 to 10 mM) and anodic peak currents with R2 = 0.954 was obtained. It was found that the diffusion of glucose was the limiting step in the electrochemical reaction. The sensor exhibited good selectivity toward glucose in the presence of 10-folds uric acid and ascorbic acid. Moreover, this sensor showed good long-term stability for continuous glucose monitoring. The good selectivity, stability, and rapid response of this sensor suggests that it could have potential applications in long-term non-enzymatic blood glucose monitoring.

Novel synthesis of carbon nanofiber aerogels from coconut matrix for the electrochemical detection of glucose

Bacterial cellulose aerogels (BCAs) were obtained from a delicious food grade coconut. Following with a simple process of carbonized calcination (700 °C~1100 °C). The obtained coconut matrix carbon nanofiber aerogels (CMCNFs) exhibit low density (≤3.47 mg/cm3), high surface area (≥1102 m2/g), and high porosity (≈99.6%), which are much higher than those of common BCAs owing to the removal of hydrogen, oxygen and other elements along with only small volume changes. Due to the flexibility of the nanofiber matrix of our presoma, the three-dimensional network micro-structure is preserved during high temperature carbonization process. The obtained CMCNFs show an excellent conductivity bearing a direct electron transfer process between glucose oxidase (GOx) and electrode surface in the electrochemical processes. It was discovered that CMCNFs can achieve a fast direct electron transfer (DET) of GOx to the rapid detection of glucose. This character should be related to the three-dimensional pore structure determined by carbonization temperature, which has been proved that the CMCNFs calcined at 1000 °C possesses the best capabilities. With merits above, a highly sensitive glucose sensor is successfully prepared by the simple carbonization of coconut cellulose matrix, which expands the application scope of bacterial cellulose aerogels. This work also offers insights for the future develop of protein-based electrochemical devices.

A Non-enzymatic Electrochemical Sensor for Glucose Detection Based on Ag@TiO2@ Metal-Organic Framework (ZIF-67) Nanocomposite.

This work presents the preparation of an efficient and sensitive glucose sensor for the detection of glucose in an alkaline media. The glucose sensor is composed of a metal organic framework (MOF) composite comprising Ag@TiO2 nanoparticles. The hybrid of Ag@TiO2 encapsulated in ZIF-67 was synthesized by the solvothermal method and applied onto a glassy carbon electrode (GCE) for the non-enzymatic sensing of glucose. The porosity of ZIF-67 was favorable for the unhindered diffusion and entrapment of glucose and its cavities served as reaction vessels. The electrochemical behavior of Ag@TiO2@ZIF-67 showed amplified results when compared with that of Ag@TiO2 and ZIF-67. Cyclic tests toward the oxidation of glucose has demonstrated excellent stability of a MOF-based hybrid sensor. The sensor based on Ag@TiO2@ZIF-67 showed high sensitivity of 0.788 μAμM−1cm−2 with a linear concentration range of 48 μM−1 mM and a response time of 5 s with an excellent detection limit of 0.99 μM (S/N = 3).

A Novel Non‐enzymatic Selective and Sensitive Glucose Sensor Based on Nickel‐Copper Oxide@3D‐rGO/MWCNTs

AbstractIn this work, a modified 3D‐rGO/MWCNT with nickel and copper oxide nanoparticles were synthesized. The structural properties of this nanocomposite were investigated by several techniques. The fabricated sensor at optimum condition potential of +0.60 V (vs. Ag/AgCl) and a rotational rate of 1800 rpm gave a detection limit of 0.04 μmol L−1 with two dynamic ranges of 0.10–300 and 300–900 μmol L−1 glucose with high stability. The good accuracy of the fabricated sensor was proved in the determination of glucose in a blood sample (with recoveries between 95 % to 105 % and RSDs of 1.2 to 2.5 %).

Highly sensitive nonenzymetic glucose sensing based on multicomponent hierarchical NiCo-LDH/CCCH/CuF nanostructures

A highly sensitive nonenzymetic electrochemical glucose sensor was developed by using a multicomponent sensing electrode made of nickel cobalt layered double hydroxide (NiCo-LDH) and cobalt copper carbonate hydroxide (CCCH) hierarchical nanostructure on Cu foam (NiCo-LDH/CCCH/CuF). The results of electrochemical measurements show that both the large accessible surface area of hierarchical nanostructure and the good conductivity of Cu foam are in favor of electrocatalysis so that the glucose detection. We have systematically evaluated the catalytic performance of NiCo-LDH/CCCH/CuF systems by changing the Ni:Co mole ratio and the synthesis time based on both cyclic voltammetry and amperometry techniques. Our results indicate that the optimization NiCo-LDH/CCCH/CuF system exhibits high sensitivity (10.78 μA/μM/cm2), large linear concentration range (0.0011.5 mM) and fast response-recovery times (2.4 s and 2.0 s) for glucose analyses. By integrating the NiCo-LDH/CCCH/CuF glucose sensing electrode with the custom-printed circuit board (PCB), we also demonstrate the feasibility of glucose detection at micromole level. Therefore, the NiCo-LDH/CCCH/CuF hierarchical nanostructure is applicable to the high sensitivity glucose determination.

Glucose Biosensor Based on Disposable Activated Carbon Electrodes Modified with Platinum Nanoparticles Electrodeposited on Poly(Azure A).

Herein, a novel electrochemical glucose biosensor based on glucose oxidase (GOx) immobilized on a surface containing platinum nanoparticles (PtNPs) electrodeposited on poly(Azure A) (PAA) previously electropolymerized on activated screen-printed carbon electrodes (GOx-PtNPs-PAA-aSPCEs) is reported. The resulting electrochemical biosensor was validated towards glucose oxidation in real samples and further electrochemical measurement associated with the generated H2O2. The electrochemical biosensor showed an excellent sensitivity (42.7 μA mM−1 cm−2), limit of detection (7.6 μM), linear range (20 μM–2.3 mM), and good selectivity towards glucose determination. Furthermore, and most importantly, the detection of glucose was performed at a low potential (0.2 V vs. Ag). The high performance of the electrochemical biosensor was explained through surface exploration using field emission SEM, XPS, and impedance measurements. The electrochemical biosensor was successfully applied to glucose quantification in several real samples (commercial juices and a plant cell culture medium), exhibiting a high accuracy when compared with a classical spectrophotometric method. This electrochemical biosensor can be easily prepared and opens up a good alternative in the development of new sensitive glucose sensors.

Room temperature ultrafast synthesis of zinc oxide nanomaterials via hydride generation for non-enzymatic glucose detection

A highly sensitive electrochemical non-enzymatic glucose (Glu) sensor has been developed based on zinc oxide nanomaterials (ZnO NMs), which was synthesized by a novel and ultrafast strategy based on headspace hydride generation (HG) at room temperature (RT). The preparation of ZnO NMs was performed in gas–solid phase by introducing ZnH2 gas (generated on-line by reducing Zn2+ with KBH4) into carbon cloth (CC) in a sealed headspace bottle. ZnH2 was unstable, can easily decompose and react with O2 in the headspace bottle to form ZnO NMs on CC. The whole preparation process was completed in minute-level under ambient conditions, which was utilized to be a feasible catalyst electrode for highly sensitive Glu sensing afterwards. It is found that the developed sensor has an excellent glucose sensing performance with high corresponding sensitivity of 4792 μA mM−1 cm−2, which was better than other ZnO-based catalysts reported. The measurement results indicate that ZnO/CC presents a short response time of less than 3 s, a wide linear range from 1 μM to 1.45 mM, a low detection of limit (LOD) of 0.43 μM (S/N = 3). Besides, the possible mechanism was discussed. Glu in serum samples has been detected with satisfactory results by the proposed material.

Needle-shaped glucose sensor based on polypyrrole doped with glucose oxidase

We demonstrate a highly sensitive enzymatic glucose sensor fabricated by screen printing. To enhance the sensitivity of the sensor, the electrode base was first modified by gold nanoparticles (AuNPs) deposition. Glucose oxidase (GOx) immobilization on the electrode was achieved by pyrrole polymerization using chemical doping method. The fabricated sensor was characterized using optical microscope and scanning electron microscope (SEM) and electrochemical experiments. The glucose detection was performed in 0.1 M phosphate buffer saline (PBS, pH 7.4) solution at operating potential of +0.4 V using amperometric i-t curve. The sensor exhibited a high and reproducible sensitivity of 14.453 nA/mM, response time ~25 s, linear range from 1 mM to 10 mM (R2 = 0.9946) and long-term stability up to 30 days in vitro.

Non-enzymatic sensor based on nitrogen-doped graphene modified with Pd nano-particles and NiAl layered double hydroxide for glucose determination in blood

Herein, a novel highly sensitive and selective non-enzymatic glucose sensor was developed. This sensor was prepared with a one-step electrodeposition process, which means that the palladium nanoparticles and NiAl layered double hydroxide were electrosynthesized simultaneously (Pd-NiAl-LDH) on a graphite sheet electrode (GS) covered by nitrogen-doped functionalized graphene (NFG). The sensing performance was investigated by linear sweep voltammetry (LSV), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry (CA) techniques. The results revealed that the one-step electrodeposition of Pd-NiAl-LDH nanocomposite on NFG provided a large surface area containing Ni and Pd electroactive centers and enhanced the electron transfer. This resulted in a remarkable effect on signal amplification toward glucose oxidation, with a wide linear range from 500 nM to 10 mM, an acceptable sensitivity of 315.46 μA. cm−2. dec−1 and a low detection limit of 234 nM based on a signal to noise ratio of 3. The relative standard deviation (RSD%) in all detection tests was lower than 5% and also the performance of fabricated GS/NFG/Pd-NiAl-LDH electrode which investigated in human real samples including serum, plasma and blood was acceptable, indicating the ability of the fabricated sensor in biological and clinical applications.

Cover Feature: Lamellar FeOcPc‐Ni/GO Composite‐Based Enzymeless Glucose Sensor (ChemElectroChem 12/2020)

The Cover Feature illustrates the nanocomposite material FeOcPc−Ni/GO made of stacked graphene oxide sheets covered with carboxylated iron phthalocyanine molecules connected through ultra-small nickel hydroxide nanoparticles, providing a very effective electrocatalyst for glucose sensing based on its oxidation to gluconic acid in aqueous media. Reproducible, high signal-to-noise ratio responses were achieved at potentials as low as +0.5 V (at the right side), realizing a sensitive and robust amperometric non-enzymatic glucose sensor as a consequence of synergic effects, as evaluated by batch injection analysis (BIA). More information can be found in the Article by B. N. Safadi et al.

Selective enhancement of non-enzymatic glucose sensor by used PVP modified on α-MoO3 nanomaterials

Among numerous metal oxide based nanocomposites, the polymer incorporated nanocomposites has received fascinated attention as promising electrode materials for inexpensive nonenzymatic glucose sensor. In this study, development of a sensitive and selective glucose sensor was fabricated using molybdenum trioxide (MoO3) via sol–gel method. The synthesized molybdenum trioxide was modified with capping molecule (wt% = 2, 4 and 6) PVP(poly-(vinylpyrrolidone)). The morphology and microstructure of the samples were examined by UV–vis diffuse reflectance spectroscopy (UV–vis-DRS), Fourier Transmission Infra-Red spectroscopy (FT-IR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and brunauer-emmett-teller (BET) analysis. The fabricated PVP modified MoO3 nanocomposites were utilized as a non-enzymatic glucose sensor in 0.1 M NaOH medium at a pH of 12 at room temperature. The synthesized nanocomposites have magnificent performance towards the detection of glucose. This is owing to enhancement effect as well as mesoporous nature of MoO3/(6%)PVP nanocomposite. The sensor demonstrates a low detection limit of 0.022 µM with a sensitivity of 86.42 µA mM−1 cm−2. It also exhibits good selectivity, stability and simplicity for the rapid detection of glucose. This sensor was opted for the determination of glucose in real sample as well.

Highly sensitive smartphone-integrated colorimetric glucose sensor based on MnFe2O4 – graphitic carbon nitride hybrid nanostructure

An extremely sensitive colorimetric glucose sensor was fabricated using a novel hybrid nanostructure comprised of manganese ferrite oxide– graphitic carbon nitride (MnFe2O4/g-C3N4). A neural network-based glucose analytical smartphone application can be used to easily monitor the glucose concentration with a high accuracy by only taking images with the smartphone camera. The as-synthesized MnFe2O4/g-C3N4 exhibited a very high affinity toward 3,3′,5,5′-tetramethylbenzidine (TMB) and H2O2, as calculated via Michaelis-Menten kinetics. The glucose sensors using as-synthesized MnFe2O4/g-C3N4 exhibit a wide linear range and very low detection limits of 20.5 nM for H2O2 and 17.3 nM for glucose, which are one of the lowest values ever reported.The instrumental analysis with XPS, XRD, and TEM revealed that MnFe2O4/g-C3N4 had a highly crystalline structure of MnFe2O4 and g-C3N4 with abundant oxygen vacancies and well-developed hybrid structures, which might result in excellent catalytic activity and glucose sensitivity.

Electrodeposition of bimetallic NiAu alloy dendrites on carbon papers as highly sensitive disposable non-enzymatic glucose sensors

The bimetallic NiAu alloy dendrites were directly grown on the carbon papers using template free electrodeposition approaches, which demonstrated superior non-enzymatic glucose sensing performance. The enhanced electrochemical performance may be due to the dendrite structure and the low charge transfer resistance originating from the synergistic effect of Ni and Au.

In situ formation of Co3O4 hollow nanocubes on carbon cloth-supported NiCo2O4 nanowires and their enhanced performance in non-enzymatic glucose sensing

Diabetes is a chronic disease that can seriously affect human health. Therefore it is important to develop a rapid and highly sensitive enzyme-free glucose sensor to aid the treatment of diabetes. In this work, homogeneous NiCo2O4 nanowire arrays were synthesized in an orderly fashion on flexible carbon cloth (CC) by a facile hydrothermal method. Then well-structured zeolitic imidazolate framework (ZIF-67) nanocubes were grown in situ on the as-prepared NiCo2O4 nanowires to form a hybrid nanoarchitecture. The hierarchical structure was transformed into a Co3O4/NiCo2O4/CC composite after annealing in the air. The as-prepared electrode was put into 0.1 M NaOH, and cyclic voltammetry and amperometry were employed to investigate its electrocatalytic properties at room temperature. It was found that the Co3O4/NiCo2O4/CC electrode exhibited outstanding sensing properties towards glucose, including terrific sensitivity (12.835 mA mM−1 cm−2), a wide linear range (from 1 μM to 1.127 mM), a low detection limit (0.64 μM) and a fast response time (within 2 s). In addition, it also had excellent selectivity, reproducibility and stability. The improvement in enzyme-free glucose sensing, in addition to the high porosity and large specific surface area of metal organic framework-derived Co3O4 hollow nanocubes, can be attributed to the NiCo2O4 nanowire arrays affording fast channels for electron transfer between CC and Co3O4. Accordingly, this method, which directly prepares hierarchical composite nanomaterials on a conductive substrate, may open up a new perspective for the enhancement of non-enzymatic glucose-sensing properties.

A highly sensitive enzyme-less glucose sensor based on pnictogens and silver shell-gold core nanorod composites.

Herein, we successfully incorporated pnictogen-Au@AgNR composites, produced by mixing shear exfoliated pnictogen nanosheets with silver shell, gold core nanorods (Au@AgNRs), as novel electrode materials towards the development of a non-enzymatic electrochemical glucose sensor. The findings of this study conceptually prove the feasibility of incorporating pnictogen-based composites for future development of electrochemical sensors.