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The assembly of α-synuclein (αS) oligomers is recognized as the main pathological driver of synucleinopathies. While the elimination of toxic αS oligomers shows promise for the treatment of Parkinson's disease (PD), the discovery of αS oligomer degradation drugs has been hindered by the lack of proper drug screening tools. Here, we report a drug screening platform for monitoring the efficacy of αS-oligomer-degrading drugs using amyloid-shelled gold nanocomplexes (ASGNs). We fabricate ASGNs in the presence of dopamine, mimicking the in vivo generation process of pathological αS oligomers. To test our platform, the first of its kind for PD drugs, we use αS-degrading proteases and various small molecular substances that have shown efficacy in PD treatment. We demonstrate that the ASGN-based in vitro platform has strong potential to discover effective αS-oligomer-targeting drugs, and thus it may reduce the attrition problem in drug discovery for PD treatment.

Highly sensitive rapid testing for COVID-19 is essential for minimizing virus transmission, especially before the onset of symptoms and in asymptomatic cases. Here, we report bioengineered enrichment tools for lateral flow assays (LFAs) with enhanced sensitivity and specificity (BEETLES2), achieving enrichment of SARS-CoV-2 viruses, nucleocapsid (N) proteins and immunoglobulin G (IgG) with 3-minute operation. The limit of detection is improved up to 20-fold. We apply this method to clinical samples, including 83% with either intermediate (35%) or low viral loads (48%), collected from 62 individuals (n = 42 for positive and n = 20 for healthy controls). We observe diagnostic sensitivity, specificity, and accuracy of 88.1%, 100%, and 91.9%, respectively, compared with commercial LFAs alone achieving 14.29%, 100%, and 41.94%, respectively. BEETLES2, with permselectivity and tunability, can enrich the SARS-CoV-2 virus, N proteins, and IgG in the nasopharyngeal/oropharyngeal swab, saliva, and blood serum, enabling reliable and sensitive point-of-care testing, facilitating fast early diagnosis.

Proteolysis of amyloids is related to prevention and treatment of amyloidosis. What if the conditions for proteolysis were the same to those for amyloid formation? For example, pepsin, a gastric protease is activated in an acidic environment, which, interestingly, is also a condition that induces the amyloid formation. Here, we investigate the competition reactions between proteolysis and synthesis of amyloid under pepsin-activated conditions. The changes in the quantities and nanomechanical properties of amyloids after pepsin treatment were examined by fluorescence assay, circular dichroism and atomic force microscopy. We found that, in the case of pepsin-resistant amyloid, a secondary reaction can be accelerated, thereby proliferating amyloids. Moreover, after this reaction, the amyloid became 32.4 % thicker and 24.2 % stiffer than the original one. Our results suggest a new insight into the proteolysis-driven proliferation and rigidification of pepsin-resistant amyloids.

The fast measurement of fibrinogen is essential in evaluating life-threatening sepsis and cardiovascular diseases. Here, we aim to utilize biomimetic plasmonic Au nanoparticles using red blood cell membranes (RBCM-AuNPs) and demonstrate nanoscale coagulation-inspired fibrinogen detection via cross-linking between RBCM-AuNPs. The proposed biomimetic RBCM-AuNPs are highly suitable for fibrinogen detection because hemagglutination, occurring in the presence of fibrinogen, induces a shift in the localized surface plasmon resonance of the NPs. Specifically, when the two ends of the fibrinogen protein are bound to receptors on separate RBCM-AuNPs, cross-linking of the RBCM-AuNPs occurs, yielding a corresponding plasmon shift within 10 min. This coagulation-inspired fibrinogen detection method, with a low sample volume, high selectivity, and high speed, could facilitate the diagnosis of sepsis and cardiovascular diseases.

Colorimetric glucose sensors using enzyme-coronated gold nanoparticles have been developed for high-throughput assays to monitor the blood glucose levels of diabetic patients. Although those sensors have shown sensitivity and wide linear detection ranges, they suffer from poor selectivity and stability in detecting blood glucose, which has limited their practical use. To address this limitation, herein, we functionalized glucose-oxidase-coronated gold nanoparticles with an erythrocyte membrane (EM-GOx-GNPs). Because the erythrocyte membrane (EM) selectively facilitates the permeation of glucose via glucose transporter-1 (GLUT1), the functionalization of GOx-GNPs with EM improved the stability, selectivity (3.3- to 15.8-fold higher), and limit of detection (LOD). Both membrane proteins, GLUT1 and aquaporin-1 (AQP1), on EM were shown to be key components for selective glucose detection by treatment with their inhibitors. Moreover, we demonstrated the stability of EM-GOx-GNPs in high-antioxidant-concentration conditions, under long-term storage (∼4 weeks) and a freeze-thaw cycle. Selectivity of the EM-GOx-GNPs against other saccharides was increased, which improved the LOD in phosphate-buffered saline and human serum. Our results indicated that the functionalization of colorimetric glucose sensors with EM is beneficial for improving selectivity and stability, which may make them candidates for use in a practical glucose sensor.

Graphene-based e-textile gas sensors have received significant attention as wearable electronic devices for human healthcare and environmental monitoring. Theoretically, more the attached graphene on the devices, better is the gas-sensing performance. However, it has been hampered by poor adhesion between graphene and textile platforms. Meanwhile, amyloid nanofibrils are reputed for their ability to improve adhesion between materials, including between graphene and microorganisms. Despite that fact, there has been no attempt to apply amyloid nanofibrils to fabricate graphene-based e-textiles. By biomimicking the adhesion ability of amyloid nanofibrils, herein, we developed a graphene-amyloid nanofibril hybrid e-textile yarn (RGO/amyloid nanofibril/CY) for the detection of NO2. Compared to traditional e-textile yarn, the RGO/amyloid nanofibril/CY showed better performance in response time, sensing efficiency, sensitivity, and selectivity for NO2. Last, we suggested a practical use of RGO/amyloid nanofibril/CY combined with a light-emitting diode as a wearable e-textile gas sensor.

Graphene-based electronic textile (e-textile) gas sensors have been developed for detecting hazardous NO2 gas. For the e-textile gas sensor, electrical conductivity is a critical factor because it directly affects its sensitivity. To obtain a highly conductive e-textile, biomolecules have been used for gluing the graphene to the textile surface, though there remain areas to improve, such as poor conductivity and flexibility. Herein, we have developed a dopamine-graphene hybrid electronic textile yarn (DGY) where the dopamine is used as a bio-inspired adhesive to attach graphene to the surface of yarns. The DGY shows improved electrical conductivity (∼40 times) compared to conventional graphene-based e-textile yarns with no glue. Moreover, it exhibited improved sensing performance in terms of short response time (∼2 min), high sensitivity (0.02 μA/ppm), and selectivity toward NO2. The mechanical flexibility and durability of the DGY were examined through a 1000-cycle bending test. For a practical application, the DGY was attempted to detect the NOx emitted from vehicles, including gasoline, diesel, and fuel cell electric vehicles. Our results demonstrated that the DGYs-as a graphene-based e-textile gas sensor for detecting NO2-are simple to fabricate, cheap, disposable, and mechanically stable.

In the development of enzymatic glucose sensors, accurate glucose sensing has been a challenging task because of the existence of numerous interfering molecules in the blood. Meanwhile, red blood cells (RBCs) selectively uptake glucose via a membrane protein called glucose transporter-1. In this study, we developed the RBC membrane (RBCM)-coated enzymatic glucose sensors that mimic the glucose uptake. The RBCM-coated sensors were examined via scanning electron microscopy, atomic force microscopy, and ATR-FTIR. We optimized the glucose permeability of the RBCM filter by controlling the thickness of the filter. The sensing range of the optimized sensor was 1-15 mM, the detection limit was 0.66 mM, and the sensitivity was 2.978 μA mM-1. Intriguingly, the RBCM-coated sensor was highly accurate and precise, despite the coexistence of glucose and interfering molecules (e.g., mannose, galactose, ascorbic acid, uric acid, and cysteine). For each interfering molecule, the errors of our sensor were 0.8 to 2.3%, which was 4.8-14.2 times more accurate than the uncoated one. A similar result was verified for a human serum sample containing countless interfering molecules. Also, the sensing performance of the sensor was consistent after 4 weeks of storage. The results suggest that applying RBCM may improve the selectivity of various types of glucose sensors including the continuous monitoring system.

A lateral flow assay (LFA) platform is a powerful tool for point-of-care testing (POCT), especially for self-testing. Although the LFA platform provides a simple and disposable tool for Coronavirus disease of 2019 (COVID-19) antigen (Ag) and antibody (Ab) screening tests, the lower sensitivity for low virus titers has been a bottleneck for practical applications. Herein, we report the combination of a microfluidic paper-based nanoelectrokinetic (NEK) preconcentrator and an LFA platform for enhancing the sensitivity and limit of detection (LOD). Biomarkers were electrokinetically preconcentrated onto a specific layer using the NEK preconcentrator, which was then coupled with LFA diagnostic devices for enhanced performance. Using this nanoelectrokinetic-assisted LFA (NEK-LFA) platform for self-testing, the severe acute respiratory syndrome coronavirus 2 Immunoglobulin G (SARS-CoV-2 IgG) sample was preconcentrated from serum samples. After preconcentration, the LOD of the LFA was enhanced by 32-fold, with an increase in analytical sensitivity (16.4%), which may offer a new opportunity for POCT and self-testing, especially in the COVID-19 pandemic and endemic global context.

Graphene electronic textiles (e-textiles) have attracted significant attention in various sensing applications owing to their strong advantages. During the fabrication of these textiles, there are factors to consider, such as electrical conductivity, mechanical flexibility, weight, and applicability in other practical applications. Bioinspired lotus fiber has appropriate advantages to be used as graphene e-textiles, including lightweight (2 gas molecules within a short exposure time (~3 min), including a low detection limit (~1 ppm), selectivity, and resistance to relative humidity. Moreover, we verified the mechanical flexibility of RGOLF through a 1,000-cycle bending test. These results suggest that the bioinspired RGOLF could be used as a gas sensor in environmental air with a strong potential for use in various wearable applications.

Cell spheroids are three-dimensional cell aggregates that have been widely employed in tissue engineering. Spheroid encapsulation has been explored as a method to enhance cell-cell interactions. However, the effect of hydrogel mechanical properties on spheroids, specifically soft hydrogels (1 kPa), has not yet been studied. In this study, we determined the effect of encapsulation of stem cell spheroids by hydrogels crosslinked with different concentrations of gelatin methacryloyl (GelMA) on the functions of the stem cells. To this end, human adipose-derived stem cell (ADSC) spheroids with a defined size were prepared, and spheroid-laden hydrogels with various concentrations (5, 10, 15%) were fabricated. The apoptotic index of cells from spheroids encapsulated in the 15% hydrogel was high. The migration distance was five-fold higher in cells encapsulated in the 5% hydrogel than the 10% hydrogel. After 14 days of culture, cells from spheroids in the 5% hydrogel were observed to have spread and proliferated. Osteogenic factor and pro-angiogenic factor production in the 15% hydrogel was high. Collectively, our results indicate that the functionality of spheroids can be regulated by the mechanical properties of hydrogel, even under 1 kPa. These results indicate that spheroid-laden hydrogels are suitable for use in 3D tissue construction.

Enzymatic blood glucose detection with selectivity is one of the most important conundrums, because human blood contains many components that can hinder enzyme-substrate reactions. Meanwhile, cancer cells express much higher levels of glucose transporter-1 on their cell membrane to selectively and excessively uptake more α-D-glucose than do normal cells. Inspired by such cellular permselectivity for glucose, herein we significantly improved the selectivity of a glucose sensor by using a breast cancer cell membrane (BCCM). The BCCM was extracted from MDA-MB-231 cells and coated onto an enzyme-deposited electrode via a vesicle fusion method. We investigated BCCM-coated sensors using ATR-FTIR, SEM, AFM, and cyclic voltammetry. The exceptional permselectivity of BCCM-coated sensors was validated using glucose solutions containing various interfering molecules (e.g., D-(−)-fructose, D-(+)-xylose, D-(+)-maltose, L-cysteine, L-ascorbic acid, and uric acid) and human serum (4.35–7.35 mM of glucose), implying their high potential for practical use.

Hydroxyapatite nanoparticle-complexed collagen (HAP/Col) hydrogels have been widely used in biomedical applications as a scaffold for controlled drug release (DR). The time-variant mechanical properties (Young's modulus, E) of HAP/Col hydrogels are highly relevant to the precise and efficient control of DR. However, the correlation between the DR and the E of hydrogels remains unclear because of the lack of a nondestructive and continuous measuring system. To reveal the correlations, herein, we investigate the time-variant behavior of E for HAP/Col hydrogels during 28 days using the atomic force microscopy (AFM) nanoindentation technique. The initial E of hydrogels was controlled from 200 to 9000 Pa by the addition of HAPs. Subsequently, we analyzed the relationship between the DR of the hydrogels and the changes in their mechanical properties (ΔE) during hydrogel degradation. Interestingly, the higher the initial E value of HAP/Col hydrogels is, the higher is the rate of hydrogel degradation over time. However, the DR of hydrogels with higher initial E appeared to be significantly delayed by up to 40% at a maximum. The results indicate that adding an appropriate amount of HAPs into hydrogels plays a crucial role in determining the initial E and their degradation rate, which can contribute to the properties that prolong DR. Our findings may provide insights into designing hydrogels for biomedical applications such as bone regeneration and drug-delivery systems.

The generation of toxic amyloid β (Aβ) oligomers is a central feature of the onset and progression of Alzheimer’s disease (AD). Drug discoveries for Aβ oligomer degradation have been hampered by the difficulty of Aβ oligomer purification and a lack of screening tools. Here, we report a plasmonic nanoparticle amyloid corona (PNAC) for quantifying the efficacy of Aβ oligomeric aggregate-degrading drugs. Our strategy is to monitor the drug-induced degradation of oligomeric aggregates by analyzing the colorimetric responses of PNACs. To test our strategy, we use Aβ-degrading proteases (protease XIV and MMP-9) and subsequently various small-molecule substances that have shown benefits in the treatment of AD. We demonstrate that this strategy with PNAC can identify effective drugs for eliminating oligomeric aggregates. Thus, this approach presents an appealing opportunity to reduce attrition problems in drug discovery for AD treatment., Effective screening of drugs to treat amyloid oligomeric aggregates associated with Alzheimer’s is needed for drug development. Here the authors report on the creation of an amyloid corona around a plasmonic nanoparticle to monitor amyloid degradation when exposed to potential drugs and demonstrate application.

The clinical use of bioactive molecules in bone regeneration has been known to have side effects, which result from uncontrolled and supraphysiological doses. In this study, we demonstrated the synergistic effect of two bioactive molecules, bone morphogenic protein-2 (BMP-2) and alendronate (ALN), by releasing them in a sequential manner. Collagen-hydroxyapatite composite scaffolds functionalized using BMP-2 are loaded with biodegradable microspheres where ALN is encapsulated. The results indicate an initial release of BMP-2 for a few days, followed by the sequential release of ALN after two weeks. The composite scaffolds significantly increase osteogenic activity owing to the synergistic effect of BMP-2 and ALN. Enhanced bone regeneration was identified at eight weeks post-implantation in the rat 8-mm critical-sized defect. Our findings suggest that the sequential delivery of BMP-2 and ALN from the scaffolds results in a synergistic effect on bone regeneration, which is unprecedented. Therefore, such a system exhibits potential for the application of cell-free tissue engineering.

The future of sensing and diagnostic devices for developing countries should be, as described by the World Health Organization (WHO), ASSURED: Affordable, Sensitive, Specific, User-friendly, Rapid and robust, Equipment free, and Deliverable to end users [1]. Paper-based sensors using colorimetric approaches are significant because they feature all key factors for ideal diagnostic devices. Conventional sensors, such as enzyme-linked immunosorbent assay (ELISA), are bulky and complex, requiring different functional blocks including transducers, processing units, detection units, and so on, which can delay sensor response [2]. Current technology based on colorimetry is concerned with the miniaturization of size, decreasing cost, permitting in situ use, and achieving freedom from additional instruments. Moreover, colorimetric sensors can be used for the instantaneous detection of analytes (e.g., protein, DNA, small molecules, etc.), by showing a visually detectable color change [3]. The color change or intensity is proportional to the analyte concentration, which indicates that colorimetric assays have capacities beyond binary sensing.

The coronavirus disease (COVID-19) pandemic has spread to nearly every corner of the globe, significantly impacting economies and societies. Despite advances in detection technologies that target viral pathogens, all countries are facing an unprecedented need to perform biosensing in a rapid, sensitive, selective, and reliable way to deal with global and urgent problems. To date, the reverse transcription-polymerase chain reaction has been the gold-standard method for COVID-19 diagnosis. However, it requires complex facilities and elaborate training and is hampered by limited testing capacity and delayed results. Herein, we review state-of-the-art research into point-of-care biosensors for early severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) detection. We include a general description of the nanotechnological techniques used to develop biosensors, along with the latest research into various biosensors for SARS-CoV-2 detection and a summary of their limitations for practical use. Finally, we discuss future perspectives and directions. This critical review offers the biosensor community insight into how to progress the present research, which may streamline the removal of the problems facing rapid and large-scale SARS-CoV-2 screening.

Alzheimer's disease (AD) is a neurodegenerative disease that accounts for 70% of all dementia. Early stage diagnosis of AD is essential as there is no certain treatment after the lesion has progressed in the late stage. Nevertheless, there are still limitations of early diagnosis of AD using neuroimaging and psychological memory assessments. Here, we demonstrate ultrasensitive and multiplexed detection of pivotal AD biomarkers (Aβ1-42 and t-Tau) in biofluids using a reduced graphene oxide field-effect transistor (gFET). The proposed approach provides a wide logarithmically linear range of detection from 10−1–105 pg mL−1 and a femtomolar-level limit of detection in biofluids (human plasma and artificial cerebrospinal fluid) as well as phosphate-buffered saline (PBS). Furthermore, as these core biomarkers have different surface charges in physiological conditions based on the isoelectric point (pI), we achieved a distinctive output signal for each biomarker. The gFET biosensor platform presented in this paper has great potential and can be used for early diagnosis of AD in clinical practice as well as accurate analysis based on the surface charge of the analytes.

Nitrogen dioxide (NO2) is one of the toxic gas that causes debilitating disease in the respiratory system. Due to imprudent industrial development, the need for a facile and sensitive gas detection has been grown. Here, we develop a simple and disposable NO2 gas sensor employing carbon adhesive tape (CAT) as the gas detection element. The CAT developed in this study contained a large amount of carbon black material to adsorb NO2 gas molecules. Experiments revealed that the gas molecules were bound rapidly to the CAT sensor (

Alzheimer's disease (AD) is the most common cause of neurodegenerative disorder in elderly people, and has become a social problem in aging societies globally. Amyloid-β (Aβ) aggregates (i.e., Aβ fibrils and plaques) present in the brains of AD patients are hallmarks of AD. Although various promising anti-Aβ drugs have been tested in pre-clinical and randomized controlled trials, the trial results have not yet been translated into clinical practice due to increasing time and cost of drug development. Recent investigations have addressed how the formation of Aβ aggregates is influenced by the surface of gold nanoparticles (AuNPs) to obtain a detailed understanding of the in vivo process of amyloid formation. Particularly, AuNPs catalytically provide nucleation sites to accelerate the formation of Aβ aggregates. Moreover, AuNPs have great potential as a sensing tool due to their optical property. Employing this dual function (i.e., catalytic and optical property), AuNP-based colorimetry is highlighted as a simple and innovative method for monitoring the efficacy of anti-Aβ reagents. In this review, we briefly survey important developments and designs of anti-Aβ drugs. The significance and perspectives of AuNP-based drug-screening in pharmacologic research are also discussed.

Graphene-based electronic textiles (e-textiles) have generally fabricated with one-dimensional (1D) textile (e.g., yarn) to serve as wearable devices or smart textiles for detecting hazardous gases. For an improved sensing performance, flexible 1D e-textile yarns can be woven and patterned to form two-dimensional (2D) sheets; however, these sheets suffer from batch-to-batch variations while manufacturing by hand. To address these issues, we fabricated a graphene-based electronic sheet (GES) on a polyester sheet with a uniform grid fishnet pattern. The 2D GES exhibited high conductance (∼7 μS) and sensitivity toward NO2 (0.34 μA/ppm) and NH3 (0.16 μA/ppm), which are indicative of a significantly improved performance as compared to that of the 1D e-textile yarn. Furthermore, the 2D GES not only exhibited an improved NO2 sensing response that was approximately three times higher than that of the 1D e-textile yarn but also showed other advantages, such as being 19 times lighter and 5 times thinner per unit area. Moreover, we confirmed that the GES enabled the detection of not only NO2, which is emitted from vehicle exhausts but also the NH3 present in the atmosphere and artificial breath. We also found that the GES possessed high mechanical flexibility to endure a 1,000-cycle bending test. These results suggest that the GES could be a next-generation 2D wearable gas sensor for detecting toxic environmental gases and monitoring health by exhalation.

Without appropriate treatment, Staphylococcus aureus (S. aureus) infection can cause life-threatening diseases (e.g., meningitis, pneumonia, bacteremia, and sepsis). However, a rapid and accurate point-of-care test for the infection remains challenging. The bacterium secretes α-hemolysin (Hla), which spontaneously binds to the cell membrane of erythrocyte, and eventually lyses the cell via pore formation. Taking advantage of this phenomenon, we apply the erythrocyte membrane (EM) extracted from human whole blood as a novel bioreceptor for detecting Hla, fabricating erythrocyte-camouflaged biosensors (ECB) by coating EM onto electrochemical impedance electrodes. We verify the existence of EM on the ECB by using confocal microscopy and atomic force microscopy. We demonstrate that ECBs sensitively detect Hla spiked in phosphate buffer saline and human serum. Also, the sensor shows higher sensitivity to Hla than major blood proteins, such as human serum albumin, fibrinogen, and gamma globulin. Specifically, the signal intensities for Hla are 8.8–12.7 times higher than those in the same concentration of those blood proteins. The detection limit of the ECB for Hla is 1.9 ng/ml while the dynamic range is 0.0001–1 mg/ml. Finally, we validate the constant sensing performance of ECB with 99.0 ± 5.6% accuracy for 35 days of storage.

With the rapid development of nanotechnology and its associated waste stream, public concern is growing over the potential toxicity exposure to heavy metal ions poses to the human body and the environment. Herein, we report an extremely sensitive Kelvin probe force microscopy (KPFM)-based platform for detecting nanotoxic materials (e.g. Ag+) accomplished by probing the integrated surface potential differences of a single gold nanoparticle on which an interaction between probe DNA and target DNA occurs. This interaction can amplify the surface potential of the nanoparticle owing to the coordination bond mediated by Ag+ (cytosine-Ag+-cytosine base pairs). Interestingly, compared with conventional methods, this platform is capable of extremely sensitive Ag+ detection (∼1 fM) in a remarkably wide-range (1 fM to 1 μM). Furthermore, this platform enables Ag+ detection in a practical sample (general drinking water), and this KPFM-based technique may have the potential to detect other toxic heavy metal ions and single nucleotide polymorphisms by designing specific DNA sequences.

The surface potential of nanoparticles plays a key role in numerous applications, such as drug delivery and cellular uptake. The estimation of the surface potential of nanoparticles as drug carriers or contrast agents is important for the design of nanoparticle-based biomedical platforms. Herein, we report the direct measurement of the surface potential of individual gold nanorods (GNRs) via Kelvin probe force microscopy (KPFM) at the nanoscale. GNRs were capped by a surfactant, cetyltrimethylammonium bromide (CTAB), which was removed by centrifugation. CTAB removal is essential for GNR-based biomedical applications because of the cytotoxicity of CTAB. Applying KPFM analysis, we found that the mean surface potential of the GNRs became more negative as the CTAB was removed from the GNR. The results indicate that the negative charge of GNRs is covered by the electrostatic charge of the CTAB molecules. Similar trends were observed in experiments with gold nanospheres (GNS) capped by citrates. Overall, KPFM-based techniques characterize the surfactant of individual nanoparticles (i.e. GNR or GNS) with high resolution by mapping the surface potential of a single nanoparticle, which aids in designing engineered nanoparticles for biomedical applications.

Amyloid aggregates have emerged as a significant hallmark of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Although it has been recently reported that microwave heating induces amyloid aggregation compared with conventional heating methods, the mechanism of amyloid aggregate induction has remained unclear. In this study, we investigated the formation of oligomeric amyloid aggregates (OAAs) by microwave irradiation at microscale volumes of solution. Microwave irradiation of protein monomer solution triggered rapid formation of OAAs within 7 min. We characterized the formation of OAAs using atomic force microscopy, thioflavin T fluorescent assay and circular dichroism. In the microwave system, we also investigated the inhibitory effect on the formation of amyloid aggregates by L-ascorbic acid as well as enhanced amyloid aggregation by silver nanomaterials such as nanoparticles and nanowires. We believe that microwave technology has the potential to facilitate the study of amyloid aggregation in the presence of chemical agents or nanomaterials.

We developed an electrochemical enzymatic biosensor coated with red blood cell membrane (RBCM) for highly selective glucose measurement. The RBCM containing its membrane proteins (glucose transporter-1) was extracted from a human red blood cell (RBC), and then placed on an established enzymatic glucose sensor by the vesicle fusion method. In the newly fabricated glucose sensor, the RBCM plays the role in the diffusion barrier of preventing the penetration of interfering molecules, while in contrast making glucose molecules permeable. We employed scanning electron microscopy and atomic force microscopy to analyze the RBCM diffusion barriers. The performance of our glucose sensors with diffusion barriers was tested regarding selectivity to glucose against other interfering molecules, such as ascorbic acid, uric acid, and galactose. Remarkably, employing the RBCM significantly improved the selectivity and accuracy of the glucose measurement, even under human serum, compared to the uncoated sensors. This result implies that the RBCM serves well as a highly permselective layer to glucose molecules, and a diffusion barrier to other molecules.