Development of a novel method based on extraction mediated by a semipermeable membrane to determine Cd and Cr in sugar by graphite furnace atomic absorption spectrometry.

This work proposes a novel method to determine the Cd(II) and Cr(III) content in commercial sugar samples. It is based on the extraction of the analytes (as ammonium pyrrolidine dithiocarbamate complexes) into a semipermeable membrane device (SPMD) filled with CHCl3. After extraction, the SPMD was deployed and opened, and the analytes were recovered from the organic phase by back extraction with a 4.2 mol L-1 HNO3 solution. The analytes present in the acid extract were measured with graphite furnace atomic absorption spectrometry. Under optimized conditions, the limit of quantification of the method was 1.2 and 3.1 ng g-1 for Cd(II) and Cr(III), respectively. Twelve samples of different types of sugar were analyzed. In addition, a recovery test was performed to evaluate the accuracy of the method. The recovery percentage was 90 %-102 % for Cd(II) and 85.2 %-103 % for Cr(III).

Micro-positive pressure significantly decreases greenhouse gas emissions by regulating archaeal community during industrial-scale dairy manure composting.

In this study, the effects of micro-positive pressure formed by covering with a semipermeable membrane in the heating phase of dairy manure composting on greenhouse gas emissions and the mechanism of reducing methane emissions by the archaeal community were investigated. A large-scale experiment was conducted with semipermeable membrane-covered composting (SMC), forced aeration composting (FAC), and traditional static composting (TSC) groups. The results showed that the oxygen concentration and methanogen abundance were key factors in regulating methane emissions. In the heating phase of SMC, the micro-positive pressure could enhance the O2 utilization rate and heating rate, resulting in Methanobrevibacter and Methanobacterium greatly decreasing, and the abundance of mcrA decreased by 90.03%, while that of pmoA did not increase. Compared with FAC and TSC, the cumulative methane emissions in SMC decreased by 51.75% and 96.04%, respectively. Therefore, the micro-positive pressure could effectively reduce greenhouse gas emissions by inhibiting the growth of methanogens.

The use of procedural kits may reduce unscheduled central line dressing changes: A matched pre-post intervention study.

Background: Unscheduled dressing changes for central venous lines (CVLs) have been shown to increase the risk of bloodstream infections. Objective: The objective of this study is to determine if the use of an innovative dressing change kit reduces the rate of unscheduled dressing changes. Methods: This pre-post interventional study took place at a large, academic, tertiary care center in metro Detroit, Michigan, the United States. We assessed the impact of the interventional dressing change procedure kit on the rate of unscheduled dressing changes for adult patients who underwent placement of a CVL inclusive of a central catheter, peripherally inserted central catheter, or hemodialysis catheter. Data was collected for the pre-intervention cohort through electronic health records (EHRs), while data for the post-intervention cohort were collected by direct observation by trained research staff in combination with EHR data. The primary outcome was the rate of unscheduled dressing changes. Secondary outcomes included rate of unscheduled dressing changes based on admission floor type, etiology of unscheduled dressing changes, and central line-associated bloodstream infections (CLABSIs). Results: The study included a convenience sample of 1548 CVLs placed between May 2018 and June 2022 with a matched analysis including 488 catheters in each of the pre- and post-intervention groups. The results showed that the unadjusted rate of unscheduled dressing evaluations was significantly reduced from the pre-intervention group (0.21 per day) to the post-intervention group (0.13 per day) (p < .001). The adjusted rate ratio demonstrated the same trend at 1.00 pre- and 0.60 post-intervention (p < .001). Stratifying the analysis based on the highest level of care showed that the intervention was effective in reducing the unadjusted rate of unscheduled dressing evaluations for both the advanced and regular medical floor subgroups pre- to post-intervention; the advanced subgroup had an reduction from 0.22 to 0.15 per day (p = .001), while the regular medical floor subgroup had a reduction from 0.21 to 0.09 per day (p < .001). CLABSIs were similar in both groups (0.6% vs 0.8%; p = 1.00) in pre- and post-intervention groups, respectively. Discussion: Procedural kits for central line dressing changes are effective in reducing unscheduled dressing changes and may have a role in reducing CLABSI. Further studies assessing the impact of dressing change kits on cost, procedural compliance, and the precise impact on CLABSI are needed.

Evaluation of compost quality and the environmental effects of semipermeable membrane composting with poultry manure using sawdust or mushroom residue as the bulking agent.

Herein, the effects of different bulking agents (sawdust and mushroom residue), on compost quality and the environmental benefits of semipermeable film composting with poultry manure were investigated. The results show that composting with sawdust as the bulking agent resulted in greater efficiency and more cost benefits than composting with mushroom residue, and the cost of sawdust for treating an equal volume of manure was only 1/6 of that of mushroom residue. Additionally, lignin degradation and potential carbon emission reduction in the sawdust group were better than those in the mushroom residue group, and the lignin degradation efficiency of the bottom sample in the sawdust group was 48.57 %. Coupling between lignin degradation and potential carbon emission reduction was also closer in sawdust piles than in mushroom residue piles, and sawdust is more environmentally friendly. The abundance of key functional genes was higher at the bottom of each pile relative to the top and middle. Limnochordaceae, Lactobacillus and Enterococcus were the core microorganisms involved in coupling between lignin degradation and potential carbon emission reduction, and the coupled relationship was influenced by electric conductivity, ammonia nitrogen and total nitrogen in the compost piles. This study provides important data for supporting bulking agent selection in semipermeable film composting and for improving the composting process. The results have high value for compost production and process application.

Effect of different multichannel ventilation methods on aerobic composting and vegetable waste gas emissions.

Aerobic composting, especially semipermeable membrane-covered aerobic fermentation, is known to be an effective method for recycling and reducing vegetable waste. However, this approach has rarely been applied to the aerobic composting of vegetable waste; in addition, the product characteristics and GHG emissions of the composting process have not been studied in-depth. This study investigated the effect of using different structural ventilation systems on composting efficiency and greenhouse gas emissions in a semipermeable membrane-covered vegetable waste compost. The results for the groups (MV1, MV2, and MV3) with bottom ventilation plus multichannel ventilation and the group (BV) with single bottom ventilation were compared here. The MV2 group effectively increased the average temperature by 19.06% whilst also increasing the degradation rate of organic matter by 30.81%. Additionally, the germination index value reached more than 80%, 3 days in advance. Compared to those of the BV group, the CH4, N2O, and NH3 emissions of MV2 were reduced by 32.67%, 21.52%, and 22.57%, respectively, with the total greenhouse gas emissions decreasing by 24.17%. Overall, this study demonstrated a multichannel ventilation system as a new method for improving the composting efficiency of vegetable waste whilst reducing gas emissions.

Development of a Disposable Polyacrylamide Hydrogel-Based Semipermeable Membrane for Micro Ag/AgCl Reference Electrode.

Currently, Ag/AgCl-based reference electrodes are used in most electrochemical biosensors and other bioelectrochemical devices. However, standard reference electrodes are rather large and do not always fit within electrochemical cells designed for the determination of analytes in low-volume aliquots. Therefore, various designs and improvements in reference electrodes are critical for the future development of electrochemical biosensors and other bioelectrochemical devices. In this study, we explain a procedure to apply common laboratory polyacrylamide hydrogel in a semipermeable junction membrane between the Ag/AgCl reference electrode and the electrochemical cell. During this research, we have created disposable, easily scalable, and reproducible membranes suitable for the design of reference electrodes. Thus, we came up with castable semipermeable membranes for reference electrodes. Performed experiments highlighted the most suitable gel formation conditions to achieve optimal porosity. Here, Cl- ion diffusion through the designed polymeric junctions was evaluated. The designed reference electrode was also tested in a three-electrode flow system. The results show that home-built electrodes can compete with commercial products due to low reference electrode potential deviation (~3 mV), long shelf-life (up to six months), good stability, low cost, and disposability. The results show a high response rate, which makes in-house formed polyacrylamide gel junctions good membrane alternatives in the design of reference electrodes, especially for these applications where high-intensity dyes or toxic compounds are used and therefore disposable electrodes are required.

Co-composting of cattle manure and wheat straw covered with a semipermeable membrane: organic matter humification and bacterial community succession.

Semipermeable membrane-covered composting is one of the most commonly used composting technologies in northeast China, but its humification process is not yet well understood. This study employed a semipermeable membrane-covered composting system to detect the organic matter humification and bacterial community evolution patterns over the course of agricultural waste composting. Variations in physicochemical properties, humus composition, and bacterial communities were studied. The results suggested that membrane covering improved humic acid (HA) content and degree of polymerization (DP) by 9.28% and 21.57%, respectively. Bacterial analysis indicated that membrane covering reduced bacterial richness and increased bacterial diversity. Membrane covering mainly affected the bacterial community structure during thermophilic period of composting. RDA analysis revealed that membrane covering may affect the bacterial community by altering the physicochemical properties such as moisture content. Correlation analysis showed that membrane covering activated the dominant genera Saccharomonospora and Planktosalinus to participate in the formation of HS and HA in composting, thus promoting HS formation and its structural complexity. Membrane covering significantly reduced microbial metabolism during the cooling phase of composting.

Membrane-covered composting significantly decreases methane emissions and microbial pathogens: Insight into the succession of bacterial and fungal communities.

In this study, the effects of semipermeable membrane-covered on methane emissions and potential pathogens during industrial-scale composting of the solid fraction of dairy manure were investigated. The results showed that the oxygen concentration in the membrane-covered group (CT) was maintained above 10 %, and the cumulative methane emission in CT was >99 % lower than that in the control group (CK). Microbial analysis showed that the bacterial genus Thermus and the fungal genus Mycothermus were dominant in CT, and the richness and diversity of the bacterial community were greater than those of the fungal community. At the end of the composting, the relative abundance of potential bacterial pathogens in CT was 32.59 % lower than that in CK, and the relative abundance of potential fungal pathogens in each group was <2 %. Structural equation models revealed that oxygen concentration was a major factor influencing the bacterial diversity in CT, and the increase of oxygen concentration could limit methane emissions by inhibiting the growth of anaerobic bacteria. Therefore, membrane-covered composting could effectively improve compost safety and reduce methane emissions by regulating microbial community structure.

Probabilistic Risk Assessment of Polycyclic Aromatic Hydrocarbons in a Colombian Reservoir.

The purpose of this research was to evaluate the concentrations, sources and ecological risk assessment of sixteen polycyclic aromatic hydrocarbons (PAHs) present in water from the La Fe reservoir, Colombia in the months of October and November of 2017 and 2018. Concentrations of PAHs in water were measured with semipermeable membrane devices (SPMD) which allow obtaining the dissolved concentrations of the PAHs in the reservoir, emphasizing the reactivity and bioavailability in the environment. The PAHs analyses were carried out by means of gas chromatography, coupled with tandem mass spectrometry (GC/MS-MS) with triple quadrupole (QqQ). The environmental risk assessment using the estimation of risk quotient with deterministic and probabilistic method, the predictive no-effect concentration (PNEC) and environmental exposure concentration (EEC) in water indicate a negligibe risk for probabilistic method for all PAHs evaluated (RQ < 0.1).

Exploring the microbial mechanism of reducing methanogenesis during dairy manure membrane-covered aerobic composting at industrial scale.

In this study, the microbial mechanism of reducing methanogenesis during membrane-covered aerobic composting from solid dairy manure was investigated. An industrial-scale experiment was carried out to compare a static composting group (SC) and a forced aeration composting group (AC) with a semipermeable membrane-covered composting group (MC + AC). The results showed that the semipermeable membrane-covered could improve the oxygen utilization rate and inhibit the anaerobic bacterial genus Hydrogenispora and archaea order Methanobacteriales. During the membrane-covered period, the acetoclastic methanogenesis module in MC + AC, AC and SC decreased by 0.58%, 0.05% and 0.04%, respectively, and the cdhC gene in the acetoclastic pathway was found to be decreased by 65.51% only in MC + AC. Changes in methane metabolism pathways resulted in a 27.48% lower average methane concentration in MC + AC than in SC. Therefore, the semipermeable membrane-covered strategy can effectively reduce methane production during dairy manure aerobic composting by restricting the methanogenesis of the acetoclastic pathway.

Dynamic, Spontaneous Blistering of Substrate-Supported Graphene in Acidic Solutions.

We report that for monolayer and few-layer graphene on common silicon and glass substrates, acidic solutions induce fast, spontaneous generation of solution-enclosing blisters/bubbles. Using interference reflection microscopy, we monitor the blister-generating process in situ and show that at pH < ∼2, nanoscale to micrometer-sized graphene blisters, up to ∼100 nm in height, are universally generated with high surface coverages on hydrophilic, but not hydrophobic, surfaces. The spontaneously generated blisters are highly dynamic, with growth, merging, and reconfiguration occurring at second-to-minute time scales. Moreover, we show that in this dynamic system, graphene behaves as a semipermeable membrane that allows the relatively free passing of water, impeded passing of the NaCl solute, and no passing of large dye molecules. Consequently, the blister volumes can be fast and reversibly modulated by the solution osmotic pressure.

Survey of bioavailable PCDDs, PCDFs, dioxin-like PCBs, and PBBs in air, water, and sediment media using semipermeable membrane devices (SPMDs) deployed in the Hartbeespoort Dam area, South Africa.

A survey of bioavailable polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like PCBs (dl-PCBs), and polybrominated biphenyls (PBBs) from ambient air, water and sediment was performed in the Hartbeespoort Dam area in South Africa, a region where data on highly toxic Stockholm Convention persistent organic pollutants (POPs) is scanty. The sampling was designed to simulate POP bioaccumulation in benthic and aquatic dwelling organisms as well as ambient air for estimation of ecological risk. The objective was to survey the spatiotemporal distribution and fate of bioavailable priority persistent organic compounds in the Hartbeespoort Dam in summer, autumn and winter seasons and to validate the utility of a comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC-TOF) method for PCDD/F, PCB, and PBB analysis. The highest detection rates for bioavailable priority POPs were for PCB 77 and PCB 126 which were detected in 15 and 16 of the 22 samples, though the majority of the detections were < LOQ for PCB 77. Overall, PCB 126, PBB 10 and PBB 49 recorded the highest quantified bioavailable concentrations per site in SPMDs deployed in the Hartbeespoort Dam. The SPMDs deployed in air at the Magalies River site in winter recorded the highest toxic equivalency quotient (TEQ) of 29.77 pg TEQ SPMD-1. The highest TEQs recorded for SPMDs deployed in the sediment phase were 10.2, 3.3, and 3.2 pg TEQ SPMD-1, recorded at the Harbour site in summer, Dam wall in summer and Harbour in winter respectively. In water, SPMDs deployed at the Crocodile River site recorded the highest TEQ of 0.81 pg TEQ SPMD-1 in summer. TEQ data shows that air carries significant bioavailable dl-toxicity compared to the water phase, and sediment generally carries the highest dl-toxicity. Detection rates for bioavailable PBBs were generally very low, with < 3 detections being quantified above the LOQ for the majority of the sites. Statistical analysis of TEQs computed at all sites, using AVOVA shows that the dispersion of TEQs in the Hartbeespoort Dam is largely homogenous as the differences between the TEQs were insignificant (p > 0.05).

Effect of micro-aerobic conditions based on semipermeable membrane-covered on greenhouse gas emissions and bacterial community during dairy manure storage at industrial scale.

This study evaluated the greenhouse gas emissions of solid dairy manure storage with the micro-aerobic group (MA; oxygen concentration <5%) and control group (CK; oxygen concentration <1%), and explained the difference in greenhouse gas emissions by exploring bacterial community succession. The results showed that the MA remained the micro-aerobic conditions, which the maximum and average oxygen concentrations were 4.1% and 1.9%, respectively; while the average oxygen concentrations of the CK without intervention management was 0.5%. Compared with the CK, carbon dioxide and methane emissions in MA were reduced by 78.68% and 99.97%, respectively, and nitrous oxide emission was increased by almost three times with a small absolute loss, but total greenhouse gas emissions decreased by 91.23%. BugBase analysis showed that the relative abundance of aerobic bacteria in CK decreased to 0.73% on day 30, while that in MA increased to 6.56%. Genus MBA03 was significantly different between the two groups (p < 0.05) and was significantly positively correlated with carbon dioxide and methane emissions (p < 0.05). A structural equation model also revealed that the oxygen concentration and MBA03 of the MA had significant direct effects on methane emission rate (p < 0.001). The research results could provide theoretical basis and measures for directional regulation of greenhouse gas emission reduction during dairy manure storage.

Changes in abscisic acid metabolism in relation to the maturation of grapevine (Vitis vinifera L., cv. Mencía) somatic embryos.

BACKGROUND: Somatic embryogenesis in grapevines is a complex process that depends on many physiological and genetic factors. One of its main limitations is the process of precocious germination of the somatic embryos in differentiation medium. This process lowers plant conversion rates from the somatic embryos, and it is probably caused by a low endogenous abscisic acid (ABA) content. RESULTS: Precocious germination of the somatic embryos was successfully avoided by culturing grapevine cv. Mencía embryogenic aggregates over a semipermeable membrane extended on top of the differentiation medium. The weekly analysis of the endogenous ABA and ABA-glucosyl ester (ABA-GE) contents in the aggregates showed their rapid accumulation. The expression profiles of 9-cis-epoxycarotenoid dioxygenase (VvNCED1), 8'-hydroxylase (VvHyd2), UDP-glucosyltransferase (VvUGT) and ß-glucosidase (VvBG2) genes in grapevine revealed that the occurrence of a first accumulation peak of endogenous ABA in the second week of culture over the semipermeable membrane was mainly dependent on the expression of the VvNCED1 gene. A second increase in the endogenous ABA content was observed in the fourth week of culture. At this point in the culture, our results suggest that of those genes involved in ABA accumulation, one (VvNCED1) was repressed, while another (VvBG2) was activated. Similarly, of those genes related to a reduction in ABA levels, one (VvUGT) was repressed while another (VvHyd2) was activated. The relative expression level of the VvNCED1 gene in embryogenic aggregates cultured under the same conditions and treated with exogenous ABA revealed the significant downregulation of this gene. CONCLUSIONS: Our results demonstrated the involvement of ABA metabolism in the control of the maturation of grapevine somatic embryos cultured over a semipermeable membrane and two important control points for their endogenous ABA levels. Thus, subtle differences in the expression of the antagonistic genes that control ABA synthesis and degradation could be responsible for the final level of ABA during the maturation of grapevine somatic embryos in vitro. In addition, the treatment of somatic embryos with exogenous ABA suggested the feedback-based control of the expression of the VvNCED1 gene by ABA during the maturation of grapevine somatic embryos.

Petroleum hydrocarbons in semipermeable membrane devices deployed in the Northern Gulf of Mexico and Florida keys following the Deepwater Horizon incident.

The Deepwater Horizon (DWH) oil spill from April to July of 2010 contaminated Gulf of Mexico waters through release of an estimated 4.1 × 106 barrels of oil. Beginning in June of 2010, semipermeable membrane devices (SPMDs) were deployed near areas with sensitive marine habitats (Alabama Alps and Western Shelf) potentially exposed to that oil. Elevated TPAH50 concentrations, flux rates and similarity of histograms and diagnostic ratios for polycyclic aromatic hydrocarbons (PAH) from SPMDs to weathered floating oil collected during the DWH spill indicates the Alabama Alps habitats were affected. While not affected by oil from the DWH spill, the temporal pattern of PAH contamination of SPMDs deployed near the Western Shelf between July 2010 and March 2011 could indicate prevailing currents affected contaminant transport to the Western Shelf Area (East and West Flower Garden, Sonnier, and Stetson Banks) from non-DWH sources, including oil and gas exploration, shipping, and Mississippi River effluent.

Assessment of bacterial and fungal communities in a full-scale thermophilic sewage sludge composting pile under a semipermeable cover.

Bacterial and fungal communities in a full-scale composting pile were investigated, with sewage sludge and a vegetal bulking agent as starting materials. Bacillales and Actinomycetales were predominant throughout the process, showing significant abundance. Ascomycota was the predominant fungal phylum during the thermophilic phase, with a shift to Basidiomycota at the end of the process. The bulking material was the principal contributor to both communities by the end of the process, with a signal above 50%. The presence of genera, such as Pedomicrobium, Ureibacillus and Tepidimicrobium at the end of the process, and Chaetomium and Arthrographis in the maturation phase, showed an inverse correlation with indicators of organic matter stabilisation. A semipermeable cover was an effective technology for excluding pathogens. These results indicate that changes in the microbial population and their interrelation with operational variables could represent a useful tool for monitoring composting processes.

Prototype of a Smart Microfluidic Platform for the Evaluation of SARS-Cov-2 Pathogenesis, Along with Estimation of the Effectiveness of Potential Drug Candidates and Antigen-Antibody Interactions in Convalescent Plasma Therapy.

Originating in China during December 2019, the novel corona-virus, SARS-CoV-2, has created mayhem worldwide in a very short time. The outbreak has been so rapid and widespread that the only option to treat the patients was administering drugs already available in the market like chloroquine/hydroxychloroquine (an antimalarial drug) and remedesivir. A large number of patients have been cured but the attribution to survival by these drugs has been controversial. Till date, we do not have any specific drug or vaccine available for COVID-19 and the pandemic seems to be far from over. To handle the current challenges posed by the outbreak effectively, we need to employ innovative interdisciplinary approaches. Organ-on-chip (OOC), particularly lung-on-chip, is one such approach which combines the potential of microfluidics, cell culture and molecular biology into a single miniaturised platform. The device is realized to be capable of simulating in-vivo physiological responses of an organ. In the current study, an OOC, which is a multichannel 3D cell culture microfluidic device, is made via soft lithography technique, using polydimethylsiloxane-polymer and diverse polymeric porous/semipermeable membranes. Several polymer membranes i.e. PDMS, polyvinylidene fluoride (PVDF), nitrocellulose, polyester etc., integrated into the microdevices, were efficiently explored to realize their better cell-adhesion and viability property. We also propose for the application of a simple, smart and cost-effective lung-on-chip platform to study the SARS-CoV-2 pathogenesis in humans, drug toxicity testing and provide insights into antigen-antibody interactions. This platform will enable us to study multiple phenomena at a micro-level generating more reliable data and a better understanding of the underlying mechanisms of SARS-CoV-2 infection and pathogenesis.

Application of semipermeable membrane devices for long-term monitoring of polycyclic aromatic hydrocarbons at various stages of drinking water treatment.

The primary goal of the presented study was the investigation of occurrence and concentration of sixteen selected polycyclic aromatic hydrocarbons in samples from various stages of water treatment and verification of the applicability of semi-permeable membrane devices in the monitoring of drinking water. Another objective was to verify if weather seasons affect the concentration and complexity of PAHs. For these purposes, semipermeable membrane devices were installed in a surface water treatment plant located in Lower Silesia (Poland). Samples were collected monthly over a period of one year. To determine the effect of water treatment on PAH concentrations, four sampling sites were selected: raw water input, a stream of water in the pipe just before ozonation, treated water output and water after passing through the distribution system. After each month of sampling, SPMDs were exchanged for fresh ones and prepared for instrumental analysis. Concentrations of polycyclic aromatic hydrocarbons were determined by high-performance liquid chromatography (HPLC). The presented study indicates that semipermeable membrane devices can be an effective tool for the analysis of drinking water, in which organic micropollutants occur at very low concentrations.

Prolonged Corrosion Stability of a Microchip Sensor Implant during In Vivo Exposure.

A microelectronic biosensor was subjected to in vivo exposure by implanting it in the vicinity of m. trapezii (Trapezius muscle) from cattle. The implant is intended for the continuous monitoring of glucose levels, and the study aimed at evaluating the biostability of exposed semiconductor surfaces. The sensor chip was a microelectromechanical system (MEMS) prepared using 0.25 µm complementary metal-oxide-semiconductor CMOS/BiCMOS technology. Sensing is based on the principle of affinity viscometry with a sensoric assay, which is separated by a semipermeable membrane from the tissue. Outer dimensions of the otherwise hermetically sealed biosensor system were 39 × 49 × 16 mm. The test system was implanted into cattle in a subcutaneous position without running it. After 17 months, the device was explanted and analyzed by comparing it with unexposed chips and systems. Investigations focused on the MEMS chip using SEM, TEM, and elemental analysis by EDX mapping. The sensor chip turned out to be uncorroded and no diminishing of the topmost passivation layer could be determined, which contrasts remarkably with previous results on CMOS biosensors. The negligible corrosive attack is understood to be a side effect of the semipermeable membrane separating the assay from the tissue. It is concluded that the separation has enabled a prolonged biostability of the chip, which will be of relevance for biosensor implants in general.

Application of Semipermeable Membranes in Glucose Biosensing.

Glucose biosensors have received significant attention in recent years due to the escalating mortality rate of diabetes mellitus. Although there is currently no cure for diabetes mellitus, individuals living with diabetes can lead a normal life by maintaining tight control of their blood glucose levels using glucose biosensors (e.g., glucometers). Current research in the field is focused on the optimization and improvement in the performance of glucose biosensors by employing a variety of glucose selective enzymes, mediators and semipermeable membranes to improve the electron transfer between the active center of the enzyme and the electrode substrate. Herein, we summarize the different semipermeable membranes used in the fabrication of the glucose biosensor, that result in improved biosensor sensitivity, selectivity, dynamic range, response time and stability.