Over the past few decades, nanostructured conducting polymers have received great attention in several application fields, including biosensors, microelectronics, polymer batteries, actuators, energy ...conversion, and biological applications due to their excellent conductivity, stability, and ease of preparation. In the bioengineering application field, the conducting polymers were reported as excellent matrixes for the functionalization of various biological molecules and thus enhanced their performances as biosensors. In addition, combinations of metals or metal oxides nanostructures with conducting polymers result in enhancing the stability and sensitivity as the biosensing platform. Therefore, several methods have been reported for developing homogeneous metal/metal oxide nanostructures thin layer on the conducting polymer surfaces. This review will introduce the fabrications of different conducting polymers nanostructures and their composites with different shapes. We will exhibit the different techniques that can be used to develop conducting polymers nanostructures and to investigate their chemical, physical and topographical effects. Among the various biosensors, we will focus on conducting polymer-integrated electrochemical biosensors for monitoring important biological targets such as DNA, proteins, peptides, and other biological biomarkers, in addition to their applications as cell-based chips. Furthermore, the fabrication and applications of the molecularly imprinted polymer-based biosensors will be addressed in this review.
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•IO@CaCO3 shows ultrafast removal efficiency for As(V), Cr(VI) and Pb(II).•Synergistic effect enables IO@CaCO3 to purify wastewater up to drinkable level within 9min.•Adsorption ...involves both ion-exchange reaction and electrostatic interaction.•Heavy metal ion removal by IO@CaCO3 was also successful by column filtration.
A carbonate-based mesoporous magnetic adsorbent IO@CaCO3 was synthesized via a hydrothermal method. The IO@CaCO3 adsorbent removed both anionic (As(V) and Cr(VI)) and cationic (Pb(II)) heavy metal ions at a rate orders of magnitude faster than any conventional adsorbents reported to date; due to synergistic effect of needle-like IO and CaCO3, it completely removed (99.99%) the toxic heavy metal ions from wastewater in only 9min. In addition, it exhibited excellent As(V), Cr(VI), and Pb(II) removal capacities of 184.1, 251.6, and 1041.9mgg−1, respectively, over a wide pH range. The heavy metal ion adsorption mechanism involves ion-exchange reactions between the cationic/anionic heavy metal ions and the positively/negatively charged groups on the adsorbent. Along with the batch adsorption tests, heavy metal ion removal by IO@CaCO3 was also performed by column filtration, demonstrating the potential of IO@CaCO3 for use in practical applications. Moreover, the excellent removal efficiencies of the adsorbent for the heavy metal ions up to drinking water level and its easy separation by an external magnetic field enabled it to be effectively reused.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Cell-free DNA (cfDNA) has attracted significant attention due to its high potential to diagnose diseases, such as cancer. Still, its detection by amplification method has limitations because of ...false-positive signals and difficulty in designing target-specific primers. CRISPR-Cas-based fluorescent biosensors have been developed but also need the amplification step for the detection. In this study, for the first time CRISPR-Cas12a based nucleic acid amplification-free fluorescent biosensor was developed to detect cfDNA by a metal-enhanced fluorescence (MEF) using DNA-functionalized Au nanoparticle (AuNP). Upon activating the CRISPR-Cas12a complex by the target cfDNA and subsequent single-strand DNA (ssDNA) degradation between AuNP and fluorophore, MEF occurred with color changes from purple to red-purple. Using this system, breast cancer gene-1 (BRCA-1) can be detected with very high sensitivity in 30 min. This rapid and highly selective sensor can be applied to measure other nucleic acid biomarkers such as viral DNA in field-deployable and point-of-care testing (POCT) platform.
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Abstract
The human neurovascular system is a complex network of blood vessels and brain cells that is essential to the proper functioning of the brain. Researchers have become increasingly interested ...in the system for developing drugs to treat neuroinflammation. Currently, creating neurovascular models begins with animal models, followed by testing on humans in clinical trials. However, the high number of medication failures that pass through animal testing indicates that animal models do not always reflect the outcome of human clinical trials. To overcome the challenges of the issues with animal models, a neurovascular‐unit‐on‐a‐chip system is developed to accurately replicate the in vivo human neurovascular microenvironment. By replicating the human neurovascular unit, a more accurate representation of human physiology can be achieved compared to animal models. The ability to detect proinflammatory cytokines in situ and monitor physiological changes can provide an invaluable tool for evaluating the efficacy and safety of drugs. Using nanosized graphene oxide for in situ detection of inflammatory responses is an innovative approach that can advance the field of neuroinflammation research. Overall, the developed neuroinflammation‐on‐a‐chip system has the potential to provide a more efficient and effective method for developing drugs for treating neurodegenerative diseases and other central nervous system diseases.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Although fluorescence-based analytical methods have been used in intracellular analyses, their sensitivity is low for the precise analysis of intracellular proteolytic enzymes to observe cell ...apoptosis related to cancer and neurodegenerative diseases. In this study, a metal-enhanced-fluorescence (MEF)-based highly sensitive biosensor for the detection of proteolytic enzymes is proposed for the first time by using a bifunctional Au nanoparticle (AuNP), which is connected to the fluorophore by both single-stranded DNA (ssDNA) and a peptide. Once caspase-3, a proteolytic enzyme, cuts the peptide specifically, the fluorescence signal is drastically increased because the ssDNA maintains an optimal distance for the MEF. The proposed sensing method shows the highly sensitive detection of caspase-3 based on just a simple enzymatic cleavage reaction within 1 h, and caspase-3-related preapoptotic cell detection was successfully carried out with high sensitivity. The proposed sensing method is a rapid, simple, and one-step technique for the real-time monitoring of intracellular proteolytic enzymes and can be applied to the early diagnosis of cancer and neurodegenerative diseases.
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In this paper, we present techniques for automatically classifying players and tracking ball movements in basketball game video clips under poor conditions, where the camera angle dynamically shifts ...and changes. In the core of our system lies Yolo, a realtime object detection system. Given the ground truth boxes collected by our data specialists, Yolo is trained to detect the presence of objects in every video frame. In addition, Yolo uses Darknet that implements convolution neural networks to classify a detected object to a player and to recognize its jersey numbers of specific movements. By identifying players and ball possessions, we can automatically compute ball distributions that are reflected on complex networks. With original Yolo system, player movement can be interrupted, when the players move out of the frame due to camera shift and when players overlap each other on a two-dimensional frame. We have adapted Yolo to keep track of players even under such poor condition by considering contextual information available from the framework preceding and/or succeeding problematic video frames. In addition to the novel movement inference method, we provide a framework for analyzing the pass networks in various perspectives to help the managing staff to reveal critical determinants of team performance and to design better game strategies. We assess the performance of our system in terms of accuracy by making a comparison with the analytical reports generated by human experts.
Nucleic acid biomarkers have been widely used to detect various viral-associated diseases, including the recent pandemic COVID-19. The CRISPR-Cas-based trans-activating phenomenon has shown excellent ...potential for developing sensitive and selective detection of nucleic acids. However, the nucleic acid amplification steps are typically required when sensitive and selective monitoring of the target nucleic acid is needed. To overcome the aforementioned challenges, we developed a CRISPR-Cas12a-based nucleic acid amplification-free biosensor by a surface-enhanced Raman spectroscopy (SERS)-assisted ultrasensitive detection system. We integrated the activated CRISPR-Cas12a by viral DNA with a Raman-sensitive system composed of ssDNA-immobilized Raman probe-functionalized Au nanoparticles (RAuNPs) on the graphene oxide (GO)/triangle Au nanoflower array. Using this CRISPR-based Raman-sensitive system improved the detection sensitivity of the multiviral DNAs such as hepatitis B virus (HBV), human papillomavirus 16 (HPV-16), and HPV-18 with an extremely low detection limit and vast detection range from 1 aM to 100 pM without the amplification steps. We suggest that this ultrasensitive amplification-free detection system for nucleic acids can be widely applied to the precise and early diagnosis of viral infections, cancers, and several genetic diseases.
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In situ quantitative measurements of neurotransmitter activities can provide useful insights into the underlying mechanisms of stem cell differentiation, the formation of neuronal networks, and ...neurodegenerative diseases. Currently, neurotransmitter detection methods suffer from poor spatial resolution, nonspecific detection, and a lack of in situ analysis. To address this challenge, herein, we first developed a graphene oxide (GO)-hybrid nanosurface-enhanced Raman scattering (SERS) array to detect dopamine (DA) in a selective and sensitive manner. Using the GO-hybrid nano-SERS array, we successfully measured a wide range of DA concentrations (10–4 to 10–9 M) rapidly and reliably. Moreover, the measurement of DA from differentiating neural stem cells applies to the characterization of neuronal differentiation. Given the challenges of in situ detection of neurotransmitters at the single-cell level, our developed SERS-based detection method can represent a unique tool for investigating single-cell signaling pathways associated with DA, or other neurotransmitters, and their roles in neurological processes.
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The modified International Standard Classification of Occupations (ISCO) has been used empirically to report or investigate working conditions or worker status. We used principal component analysis ...and k-means clustering to analyze the working population based on 67 occupational characteristics among 23,060 workers from the fourth Korean Working Conditions Survey in 2014. The three-cluster approach classified workers into major groups 1–4 (managers, professionals, technicians, and clerical support workers), 5–6 (service, sales, agricultural, forestry, and fishery workers), and 7–9 (crafts, trades, machine operators, assemblers, and elementary occupations) based on the ISCO-08. The results of the current study suggest a well-defined clustered occupational classification that can be used to report or investigate workers.
For the early diagnosis of several diseases, various biomarkers have been discovered and utilized through the measurement of concentrations in body fluids such as blood, urine, and saliva. The most ...representative analytical method for biomarker detection is an immunosensor, which exploits the specific antigen-antibody immunoreaction. Among diverse analytical methods, surface plasmon resonance (SPR)-based immunosensors are emerging as a potential detection platform due to high sensitivity, selectivity, and intuitive features. Particularly, SPR-based immunosensors could detect biomarkers without labeling of a specific detection probe, as typical immunosensors such as enzyme-linked immunosorbent assay (ELISA) use enzymes like horseradish peroxidase (HRP). In this review, SPR-based immunosensors utilizing noble metals such as Au and Ag as SPR-inducing factors for the measurement of different types of protein biomarkers, including viruses, microbes, and extracellular vesicles (EV), are briefly introduced.
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