Determination Of Glucose Research Articles

HPLC for simultaneous quantification of free mannose and glucose concentrations in serum: use in detection of ovarian cancer.

Background: Abnormal levels of monosaccharides in blood have been linked to tumorigenesis. In this study, a novel high-performance liquid chromatography (HPLC) method was established for the simultaneous determination of free mannose and glucose in the serum. Methods: The serum was directly derivatized by 1-phenyl-3-methyl-5-pyrazolone under alkaline conditions using L-rhamnose as an internal standard. The chromatographic separation was then performed on a Poroshell EC-C18 chromatographic column (4.6 × 100 mm, particle size 2.7μm, Agilent) with gradient elution using NH4Ac-HAc and acetonitrile as the mobile phases. The method was thereafter validated according to international guidelines. The serum samples obtained from 200 healthy individuals and 200 ovarian cancer (OC) patients were analyzed for free mannose and glucose. Results: The method was found to be reproducible for quantification within 20min and included online sample purification. The method displayed excellent linearity in the concentration range (for mannose: 0.5-500μg/mL; glucose: 0.5-1500μg/mL). The precision, recovery, and stability met the FDA bioanalytical method validation acceptance criteria. Overall, the measurement of glucose content by HPLC correlated well with the different enzymatic methods. Ovarian cancer mannose levels in the serum were significantly higher in the advanced stage (61.22μmol/L, p < 0.0001) than those in healthy volunteers and early-stage patients (44.51μmol/L versus 50.09μmol/L, p < 0.0001). The AUC for the ratio of serum free glucose to mannose (G/M) was 0.98 (p < 0.0001), with a sensitivity of 91.46% and a specificity of 98.50%, which served as a biomarker for OC diagnosis. Conclusion: We report a simple, repeatable, and attractive analytical method by HPLC, which can be used for quantitative estimation of free mannose and glucose simultaneously in human serum. Our results indicate that the serum level of mannose could be used as a potential biomarker of ovarian cancer.

Increased Lipoprotein (a) and familial hypercholesterolemia: a dangerous combination.Data from a 12-year follow-up study

Abstract Background Lipoprotein (a)[Lp(a)] is a molecule characterized by very increased atherogenicity. Mounting evidence support the causal link between high Lp(a) concentration and atherosclerotic cardiovascular (CV) disease in the general population. Purpose The role of Lp (a) in specific categories of patients at high CV risk, such as patients with familial hypercholesterolaemia (FH), is also of special importance. The aim of our study was to investigate the prognostic role of Lp (a) regarding major adverse CV outcomes in subjects with heterozygous FH. Methods 155 patients from the outpatient lipid clinic of our hospital (56 males,mean age 41.2±14.2 years, 26% smokers, 16% with diabetes mellitus), without history of CV disease, who fulfilled the FH criteria participated in the study. Participants were evaluated for a mean follow-up period of 12.4±7.1 years with at least one annual visit. Venous blood samples were obtained at baseline in all patients for the determination of plasma glucose, lipid profile and levels of Lp(a). All subjects were on lipid-lowering medication during the follow-up period. The endpoint of our study was the composite of major CV events (coronary artery disease events and stroke). Results The incidence of the composite endpoint of major CV events during the follow-up period was 9% (n=14). In the total population, the mean baseline Lp (a) levels were 34.9±33.7 mg/dl, while 42% had increased Lp (a) levels ≥30mg/dl. The group of FH patients with new-onset CV disease had higher levels of Lp(a) at baseline compared to those without new-onset CV disease (48.1±37.3 vs 33.6±33.1 mg/dl, p=0.01). Also, those with new-onset CV disease had higher percentage of increased Lp(a) levels (≥30mg/dl) at baseline compared to those without development of CV disease (71% vs 39%, p=0.02).Multiple Cox regression analysis revealed that during the follow-up period independent predictors of major adverse CV events were:increased baseline Lp(a) levels(≥30mg/dl)(HR 5.61, 95% CI 1.51-10.92, p=0.01), male sex (HR 8.11, 95% CI 2.02-12.48, p&amp;lt;0.01), baseline low-density cholesterol levels (HR 1.01, 95% CI 1.00-1.02, p=0.04) and the presence of hypertension at baseline (HR 3.59, 95% CI 1.03-12.49, p=0.04), after adjustment for confounding factors. Conclusions In patients with FH, increased baseline Lp(a) is an independent predictor of adverse CV events, after a 12-year follow-up period. FH patients with Lp (a)levels ≥30mg/dl have an almost 5-fold greater CV risk compared to those with lower Lp (a) levels. It seems that Lp (a) reclassifies the already increased CV risk of FH subjects into an even higher level.

Electrochemiluminescence Properties and Sensing Application of Zn(II)-Metal-Organic Frameworks Constructed by Mixed Ligands of Para Dicarboxylic Acids and 1,10-Phenanthroline.

Four metal-organic frameworks (MOFs) were designed and prepared through a mixed-ligand strategy by controlling the combination of various dicarboxylic acid ligands with invariant center metal and o-phenanthroline heterocyclic ligand. The regulatory effects of ligand electronic band and crystal structure on the electrochemiluminescence (ECL) characteristics of MOFs were verified by experimental results and density functional theory (DFT) calculations. The flexible chain structure of MOF-2 promotes electron transfer between MOF electroactive free radicals and the co-reactant, making it show outstanding ECL characteristics among all of the four MOFs with the luminescence quantum efficiency 8.37 times that of tris(bipyridine)-ruthenium(II) ([Ru(bpy)3]2+). Meanwhile, a new ECL mechanism for MOF luminescent crystal materials with reactive oxygen species in solvents as a co-reactant in the aqueous aerobic environment has been proposed. MOF-2 was selected to construct an ECL sensor for the determination of glucose in human urine samples. This study provides a useful idea for the development and design of new luminescent molecular crystal materials.

Relationship between free circulating DNA levels, ejection fraction and brain natriuretic peptide levels in patients with chronic heart failure: prospective observational study

BACKGROUND: Chronic heart failure (CHF) is one of the most serious problems in cardiovascular diseases, requiring accurate diagnosis and treatment. The search for new laboratory markers of CHF can improve the accuracy of diagnosis and identify the severity of the patients condition.&#x0D; AIM: Our aim was to study the relationship between the levels of free-circulating DNA (cfDNA) and brain natriuretic peptide (NT-proBNP) in the blood plasma of patients suffering from CHF with ejection fraction (EF), to investigate the relationship between these laboratory markers, and to evaluate the dynamics of changes in the studied parameters against the background of drug therapy.&#x0D; MATERIALS AND METHODS: The study involved 67 patients of both sexes with a diagnosis of CHF, verified by clinical and functional methods. 23 people without established chronic diseases formed the control group. At the stage of inclusion in the study, all patients underwent: physical examination, general blood test, biochemical blood test with determination of lipid profile, glucose, creatinine, NT-proBNP and cfDNA levels, as well as electrocardiography (ECG), electrocardiography (ECHO-CG), radiography of organs chest, ultrasound of the abdominal organs, 6-minute walk test. The level of cfDNA was determined using the method of P.P. Laktionov, S.N. Tamkovich, E.Yu. Rykova (2005). Repeated blood sampling with assessment of cfDNA and NT-proBNP levels was carried out in the group of patients with reduced ejection fraction 57 months from the start of treatment/correction of previous therapy.&#x0D; RESULTS: The study revealed significant differences in the levels of cfDNA in the blood plasma in patients with different EF (less than 40%, 4049%, 50% or more). At the same time, an inverse relationship was established between cfDNA indicators and EF, as well as between the level of NT-proBNP and EF, that is, a progressive decrease in myocardial contractility is accompanied by a combined increase in the levels of the studied markers in the blood, reflecting the severity of the patients condition. In addition, the positive effect of drug therapy on cfDNA and NT-proBNP levels in the group of patients with EF 40% has been proven.&#x0D; CONCLUSION: The identified patterns make it possible to consider the level of cfDNA in blood plasma as a potential biomarker of CHF, and also to use it for dynamic monitoring of patients.

Enhanced mimic peroxidase activity of carbon nanozyme by simultaneous phosphorus, oxygen dual-heteroatom doping and nanosheet structure construction

The carbon-based nanomaterials with peroxidase-like property show huge potential as candidates for natural enzymes. The design of carbon nanozymes with high activity can expand their potential application. Herein, the carbon nanozymes with enhanced catalytic property by simultaneous phosphorus, oxygen dual-doping and nanosheet structure construction are fabricated through one-step pyrolysis process. The dual-doped phosphorus and oxygen element is conducive to accelerate electron transfer and form active site with moderate free energy for activation of H2O2 to ·OH. Besides, the nanosheet structure with enlarged surface area is beneficial to expose more catalytic sites. Benefiting from its great peroxides-like activity, the phosphorus, oxygen dual-doped carbon nanosheet materials (POCNS) are used in colorimetric determination of H2O2 and glucose with cascade reaction of glucose oxidase and POCNS. And the sensitive colorimetric detection assay for organophosphorus pesticide of chlorpyrifos was constructed with regulation of peroxidase-like activity by aptamer. The system of POCNS and H2O2 further displays great antibacterial property in inactivation of Escherichia coli. This work provides an avenue to construct high-efficient carbon nanozymes and develop their potential application in environmental and biological field.

Administration of Akebia Saponin D Improved Blood Lipid Levels and Pregnancy Outcomes in Mice with Gestational Diabetes Mellitus

Gestational diabetes mellitus (GDM) is a prevalent and severe metabolic disease in pregnant women that is characterized by a high incidence. Placental oxidative stress and inflammation are recognized as the primary contributors to GDM pathogenesis. The repressive effect of akebia saponin D (ASD) on oxidative stress and inflammation has been demonstrated in various diseases. To investigate the impact of ASD on GDM. Animal experimental study. GDM mice were intraperitoneally treated with ASD. The effect of ASD on GDM symptoms, blood lipid levels, pancreatic tissue damage, gestational outcomes, oxidative stress, and inflammation was assessed via intraperitoneal glucose and insulin tolerance tests, serum glucose and insulin level determination, lipid biochemistry analysis, pathological staining, oxidative stress evaluation, western blot analysis, and enzyme-linked immunosorbent assay. ASD reduced the GDM-induced increase in body weight and blood glucose levels while restoring the decreased insulin levels associated with GDM. In addition, ASD improved the serum lipid parameters, pancreatic tissue damage, and gestational outcomes in GDM mice. Furthermore, ASD reversed the decreased levels of superoxide dismutase and glutathione while reducing the elevated concentrations of malondialdehyde and myeloperoxidase in GDM mice. In addition, ASD rescued the relative protein expression of nuclear factor-E2-related factor 2 and heme oxygenase-1 in the placenta of GDM mice. Additionally, ASD counteracted the increase in tumor necrosis factor-α, interleukin (IL)-6, and IL-1β levels in the sera and placenta of GDM mice. ASD suppressed oxidative stress and inflammation to effectively relieve symptoms and gestational outcomes of the GDM mice.

The Development of Reagentless Amperometric Glucose Biosensor Based on Gold Nanostructures, Prussian Blue and Glucose Oxidase.

Precise blood glucose detection plays a crucial role in diagnosing and medicating diabetes, in addition to aiding diabetic patients in effectively managing their condition. In this research, a first-generation reagentless amperometric glucose biosensor was developed by combining the graphite rod (GR) electrode modification by gold nanostructures (AuNS) and Prussian blue (PB) with glucose oxidase (GOx)-an enzyme that can oxidize glucose and produce H2O2. Firstly, AuNS was electrochemically deposited on the GR electrode (AuNS/GR), and then PB was electrochemically synthesized on the AuNS/GR electrode (PB/AuNS/GR). Finally, GOx was immobilized over the PB/AuNS nanocomposite with the assistance of Nafion (Nf) (Nf-GOx/PB/AuNS/GR). An application of PB in the design of a glucose biosensor enables an easy electrochemical reduction and, thus, the determination of the H2O2 produced during the GOx-catalyzed oxidation of glucose in the sample at a low operation potential of -0.05 V vs. Ag/AgCl/KCl3 mol L-1. In addition, AuNS increased the electrochemically active surface area, improved the GOx immobilization and ensured a higher analytical signal. The developed glucose biosensor based on the Nf-GOx/PB/AuNS/GR electrode exhibited a wide linear range, from 0.025 to 1 mmol L-1 of glucose, with a 0.0088 mmol L-1 limit of detection, good repeatability and high selectivity over electroactive interfering substances. The developed biosensor is convenient for the determination of glucose in the physiological environment.

Study of electrochemical biosensor for determination of glucose based on Prussian blue/gold nanoparticles-chitosan nanocomposite film sensing interface

A highly electroactive bilayer composite film sensing interface of Prussian blue (PB)/gold nanoparticles-chitosan (AuNPs-CS) was modified on Au electrode through electrochemical deposition and coating method followed by integrating glucose oxidase (GOx) into the interfacial matrix to fabricate a high-performance glucose biosensor. The excellent electrocatalytic ability of the PB/AuNPs-CS composite film sensing interface for H2O2 was evaluated, which has a broad linear response of 0.01–7.95 mM, with a low detection limit (LOD) 0.269 μM and a high sensitivity of 511.82 μA·mM−1·cm−2. The enhanced electrocatalytic activity of this sensing interface for H2O2 is attributed to the protection from the network CS film to PB and the synergistic effect of PB and AuNPs. Consequently, an electrochemical biosensing interface was constructed with GOx immobilized as a model enzyme. The PB/GOx-AuNPs-CS biosensing nanocomposite film was capable of a fast steady-state response time (within 2 s) and high sensitivity to glucose with a wide linear range of: 0.025–2.00 mM (R 2 = 0.99), with a sensitivity of 40.41 μA·mM−1·cm−2 and a LOD of 1.62 μM; and 2.00–6.50 mM (R 2 = 0.98), with a sensitivity of 8.90 μA·mM−1·cm−2 and a LOD of 7.16 μM. The biosensor has good anti-interference and selectivity, which provides a promising wide linear range platform for clinical blood glucose detection in the future.

One-pot hydrothermal synthesis of CuS/CoS composite for electrochemical non-enzymatic glucose sensor

Herein, a CuS/CoS electrode material was synthesized using a one-step hydrothermal method as an efficient electrocatalyst for a non-enzymatic glucose sensor. The nanocomposites were characterized by Field emission scanning electron microscope (FE-SEM), Transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The CuS/CoS composite loaded glassy carbon electrode was used to investigate electrochemical properties using cyclic voltammetry (CV) and chronoamperometry (CA). The results showed 314.85 μA mM−1 cm−2 sensitivity and 1.71 μM detection limit. Selectivity of the sensor was examined over potential interfering species that exhibits the distinct increased current response on addition of glucose before and after addition of interfering species evident the selectivity of CuS/CoS electrode material. Moreover, the CuS/CoS composite-based non-enzymatic glucose sensor revealed considerable stability, selectivity over interfering species, and viability for glucose determination in diluted human serum samples, which provide efficient and cost-effective strategy to develop non-enzymatic electrochemical glucose sensing platform.

Synthesis of Quaternary (Ni, Co, Cu)Se2 Nanosheet Arrays on Carbon Cloth for Non-Enzymatic Glucose Determination

Unlike transition metal oxides and sulfides, transition metal-based selenides display higher electrical conductivity, more electroactive unsaturated edge sites, and better chemical stability, which have found extensive usage in electrocatalysis. In this work, simple hydrothermal and solvothermal procedures were employed to synthesize quaternary (Ni, Co, Cu)Se2 nanosheet arrays on carbon cloth (CC) to measure glucose. The conductivity of the material can be effectively elevated by adding Se element to form selenides, and the synergistic effect between the three selenides can improve the electrocatalytic performance. Consequently, in the ranges of 0.01–600 μM and 600–9000 μM, respectively, the current response of the synthesized material to glucose concentration exhibited linear relationships. The sensor demonstrated excellent sensitivity and a low detection limit of 5.82 nM. Furthermore, the practical applicability of the constructed biosensor was proved by using it to quantify the amount of glucose in human serum.

Selection of Tools for Comprehensive Assessment of Patients with Obesity for Patient-oriented Treatment in Primary Care

In the modern world, obesity has become a large problem and now is one of the most complex medical and social problems. That is why the assessment of the health status of an obese patient is of the great importance for maintaining health, eliminating risk factors, patient-oriented treatment and improving the quality of their life. The article analyzes literature data regarding tools for complex assessment of obese patients at the level of primary health care (PHC) for the implementation of patient-oriented treatment. The bibliosemantic method and the system analysis method were used for the analysis. A systematic review of literature sources identified the most practical tools for assessing obesity at PHC level. It is noted that for clinical and instrumental assessment of the patient’s condition, anthropometric, instrumental indicators should be used: height, body weight, waist circumference, hip circumference, blood pressure; calculated indexes: Quetelet index (BMI), body surface area (BSA), waist/hip ratio (WHR), Conicity Index (ConI), A body shape index (ABSI), Abdominal Volume Index (AVI). These indicators better describe abdominal obesity and make possible to assess the risks of non-communicable diseases. Laboratory indicators include determination of fasting glucose, insulin, HOMA index, lipidogram (with determination of total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein, very low-density lipoprotein, atherogenicity index). The best tools for assessing psychosocial status and sleep were: the Dutch Eating Behavior Questionnaire (DEBQ), the Hospital Anxiety and Depression Scale (HADS), the Beck Depression Scale, the Hamilton Anxiety Scale (HAM-A), the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS). The SF-36 (36-Item Short Form Health Survey), IPAQ, FINDRISK scale should be used to assess the quality of life and risks. For a complex assessment of obese patients at the primary care level, in addition to generally accepted clinical and laboratory examinations, it is necessary to study eating behavior, anxiety and depression levels, sleep quality, quality of life, physical activity level, and the risk of diabetes in patients. This allows family doctors to improve their patient-centered approach. Due to their compactness, availability and high sensitivity, they can be widely used by general practitioners.

A biosensing array for multiplex clinical evaluation of glucose, creatinine, and uric acid

The multiplex and simultaneous determination of blood glucose, creatinine and uric acid is essential for the early screening of chronic diseases or regular disease monitoring. Here, we report for the first time a biosensing array for the multiplex and simultaneous determination of plasma glucose, creatinine and uric acid. The sensing electrodes are fabricated on a PET surface, including three working electrodes, one reference electrode, and one counter electrode. Each specific enzyme is immobilized on its corresponding working electrode. The biosensing array can exhibit high sensitivity and selectivity for the simultaneous determination of blood glucose, creatinine and uric acid in real blood samples, and the measurement results are accurate and consistent with those from the clinical biochemistry analyzer in the hospital. It is expected that this work could provide new avenues for the fundamental study of biosensing device construction, as well as practical applications of the detection of biomarkers in chronic diseases.

Synthesis of unique three-dimensional CoMn2O4@Ni(OH)2 nanocages via Kirkendall effect for non-enzymatic glucose sensing

Transition metal oxides / hydroxides, which have the advantages of wide distribution, low price, low toxicity, and stable chemical properties, have attracted much attention from researchers. Therefore, this work reports the construction of the unique CoMn2O4 nanocages assisted by the Kirkendall effect, and worm-like Ni(OH)2 nanoparticles were grown on the surface via hydrothermal method, the final product CoMn2O4@Ni(OH)2 nanocages were applied to construct efficient and sensitive non-enzymatic glucose electrochemical sensing. The stable three-dimensional hollow CoMn2O4 nanocages structure, not only can provide a wider specific surface area and more abundant active sites, its porous structure also can effectively inhibit the aggregation of nanoparticles, increase the ion diffusion path, shorten the electron transport distance, and improve the electrical conductivity. Loading Ni(OH)2 nanoparticles on the CoMn2O4 nanocages can increase catalytic sites, and further strengthen the electrocatalytic performance. Due to the good synergistic effect between CoMn2O4 and Ni(OH)2, CoMn2O4@Ni(OH)2 nanocages electrochemical sensor can achieve sensitive and rapid detection of trace glucose, with excellent linear range (8.5–1830.5 μM), low limit of detection (0.264 μM), high sensitivity of 0.00646 μA mM−1 cm−2, and outstanding repeatability. More importantly, the sensor has been successfully applied to the determination of blood glucose in human serum with good recoveries (95.64–104.3 %). This work provides a novel scheme for blood glucose detection and expands the application of transition metal oxides / hydroxides in the field of electrochemical sensing.

Colostrum traits and newborn body weight and growth: comparison between single and twin underfed sheep pregnancies.

Maternal nutrition during gestation plays an important role in colostrum production, postnatal growth, and survival of newborn lambs, especially in twin gestations. This research aimed to investigate the effects of chronic natural undernutrition on colostrum traits and early lamb's postnatal growth born from single and twin sheep pregnancies developed in a restrictive prairie, representative of southern Patagonia. Single- and twin-bearing ewes (n = 20 per group) were maintained grazing in a natural pasture. At 140 days of gestation, ewes were placed in individual pens for lambing control. Colostrum was collected immediately after delivery and at 12, 24, and 36 h postpartum, for determination of yield and composition. Maternal blood was obtained at 140 days of gestation and at lambing for plasma glucose, progesterone, 17β-estradiol, and IgG determination. Newborn lamb blood for determining glycaemia and IgG was collected at birth and at 12, 24, 36, and 120 h after birth. Lamb mortality and growth was assessed from birth until 30 days of life. No differences were observed in progesterone and 17β-estradiol. There were no differences in colostrum yields and fat components, however single- had higher values of protein and lactose than twin-bearing ewes (p < 0.05 for both). Singletons had higher glycaemia than twins at 12 h postpartum (102.2 ± 32.8 vs. 73.4 ± 29.9 mg/dL, p < 0.05). Colostrum IgG content was similar at delivery but higher in single ewes at 12 and 24 h, reaching a similar values at 36 h (4.7 ± 9.7 and 5.8 ± 7.7 mg/mL in single and twin pregnancies, respectively). Newborn IgG was higher in singletons compared to twins at least until 48 h of life. Lams body weight was always superior in singleton than twins from birth until 30 days of life. Mortality did not differ during the first week of life, but it increased significantly only in twins until day 30 of life. Undernourishment in pregnant ewes affected colostrum quantity and quality, resulting in a lower postnatal growth and a higher mortality in twins. Alternative managements favoring fetal growth, birth weight and neonatal viability in twin sheep pregnancies are needed, when flocks are breed under harsh environments.

Flexible Specific Determination of Glucose in Solution, Blood Serum, and Sweat Using a Terahertz Hydrogel‐Functionalized Metamaterial

Terahertz metamaterials have shown promises in biomolecules detection, however, aqueous solvents such as blood serum strongly absorb the terahertz waves, interfering with the detection. To avoid such interference, an ultrathin, flexible, biogel‐based metamaterial that can specifically detect the transmission of terahertz waves through biomolecules in aqueous solution is proposed and demonstrated. The glucose in water can be detected with a sensitivity of 0.0446 dL mg−1 and a detection limit of 1.64 mg dL−1, as well as glucose in human serum. The metamaterial that detects glucose in human sweat is part of a wearable device. The biosensor functions well for more than 100 detection cycles. The results suggest a strategy for real‐time detection of glucose and potentially other biomolecules.

Cell-inspired design of cascade catalysis system by 3D spatially separated active sites

Cells possess isolated compartments that spatially confine different enzymes, enabling high-efficiency enzymatic cascade reactions. Herein, we report a cell-inspired design of biomimetic cascade catalysis system by immobilizing Fe single atoms and Au nanoparticles on the inner and outer layers of three-dimensional nanocapsules, respectively. The different metal sites catalyze independently and work synergistically to enable engineered and cascade glucose detection. The biomimetic catalysis system demonstrates ~ 9.8- and 2-fold cascade activity enhancement than conventional mixing and coplanar construction systems, respectively. Furthermore, the biomimetic catalysis system is successfully demonstrated for the colorimetric glucose detection with high catalytic activity and selectivity. Also, the proposed gel-based sensor is integrated with smartphone to enable real-time and visual determination of glucose. More importantly, the gel-based sensor exhibits a high correlation with a commercial glucometer in real samples detection. These findings provide a strategy to design an efficient biomimetic catalysis system for applications in bioassays and nanobiomedicines.

Fe-Doped NiMoO4 Nanoparticles as New Non-Enzymatic Catalyst in Glucose Sensing

In this work, a new non-enzymatic sensor for the determination of glucose was constructed using Fe-doped NiMoO4 nanoparticles (NiFeMoO4). Hydrothermal and calcination techniques were successfully used to synthesis different proportion nanoparticles of Ni1−xFexMoO4 (x = 0, 0.01, 0.03, 0.05). A set of electrochemical measurements demonstrated that all of the Ni1−xFexMoO4 have electrocatalytic properties to glucose. Especially, Ni0.99Fe0.01MoO4 (x = 0.01) displayed the most excellent amperometric response to glucose in the range of 0.01∼13 mM with a limit of detection (LOD) of 0.29 μM (S/N = 3). This amperometric sensor also showed satisfactory anti-interference performance and stability. More significantly, the sensor’s applicability was tested using a glucose assay in actual serum samples with acceptable results.

Ultrasmall platinum nanoclusters densely immobilized on hairy metal organic framework for nonenzymatic glucose detection

Rational design of non-enzymatic nanomaterials that possess the similar functions to natural enzymes holds great promise in chemical and biological molecule detection. In this work, a non-enzymatic electrochemical biosensor for detection of glucose was developed based on poly(2-vinylpyridine) (P2VP) grafted UiO-66 metal organic framework decorated with ultrafine platinum nanoclusters (PtNCs). The as-fabricated UiO-66-g-P2VP/PtNCs nanocomposite was then placed on an indium tin oxide (ITO) electrode to construct non-enzymatic glucose biosensor for electrochemical detection of glucose in alkaline electrolyte. The resulting UiO-66-g-P2VP/PtNCs/ITO modified electrode showed two linear responses over glucose concentration ranging of 0.01–5 mM and 5–18 mM with a low detection limit of 2.18 μM (S/N = 3). Moreover, the UiO-66-g-P2VP/PtNCs/ITO serving as an electrochemical biosensor was successfully applied to the rapid determination of glucose in human serum sample with a desirable result. Our findings pave the way for design and development of a promising artificial enzyme for the construction of high performance sensing platform.

Development of non-precious metal oxide-based electrodes for enzyme-free glucose detection: A review

The progress of accurate and economical sensors for glucose determination is vital for the detection and treatment of diabetes. Even though electrochemical enzyme-based sensors have been widely utilized in the medical field for glucose determination, high preparation costs, and poor durability have led to the introduction of a novel type of enzyme-free sensor for glucose recognition. Non-precious metal oxides have been comprehensively explored for the preparation of affordable sensors for non-enzymatic, high-performance glucose detection. This review commences by clarifying the mechanistic aspects of electrochemical sensors for enzyme-free glucose detection, followed by advanced studies on metal oxides with different strategies, including morphology engineering, supported carbon materials, and noble metal doping for efficient glucose detection. Finally, formidable obstacles and future development of non-enzymatic electrochemical glucose sensing are also discussed.

A novel PDMS-based digital magnetofluidic platform for lab-on-a-chip applications

Superhydrophobic gold film embedded PDMS was employed as a novel platform for digital magnetofluidics. The device performance for lab-on-a-chip applications was investigated by demonstrating four types of reactions. First, acid-based titration was introduced as a simple mixing reaction. Second, colorimetric detection of phosphate based on the molybdenum blue method was represented as a more complicated reaction. The fabricated device was able to determine the amount of phosphate in the concentration range of 10–100 ppm with %RSD of color intensity of less than 5%. Third, colorimetric detection of glucose using glucose oxidase was demonstrated as an enzymatic reaction. A linear range of 1–20 mM for determination of glucose was applied for measuring glucose in beverages with recovery percentages of glucose in the acceptable range of 89.6–106.8%. Finally, multistep analysis of C-reactive protein (CRP) based on immunomagnetic separation was successfully demonstrated on this proposed device. Therefore, the superhydrophobic gold-coated PDMS has shown its ability to be a simple platform for digital magnetofluidics for a variety of applications in the field of lab-on-a-chip technology.