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Single phase, polycrystalline perovskite oxide SrVO3, with its intrinsic low effective work function and facile synthesis process, is a promising thermionic electron emitter cathode candidate, in which previous works have shown evidence of an effective work function as low as 2.3 eV. In this work, we study the vacuum activation process of SrVO3 and find that it has promising emission stability over 15 days of continuous high temperature operation. We find that SrVO3 shows surface Sr and O segregation during its operation, which we hypothesize is needed to create a positive surface dipole, leading to a low effective work function. Emission repeatability from cyclic heating and cooling suggests the promising stability of the low effective work function surface, and additional observations of drift-free emission during 1 h of continuous emission testing at high temperature further demonstrate its excellent performance stability. This assessment of the emission stability over time and the interplay of evolving surface chemistry with emission behavior are necessary for understanding how best to prepare, process, and operate SrVO3 cathodes. [ABSTRACT FROM AUTHOR]

An innovative photocatalytic fuel cell (PFC)-based self-powered system was developed by integrating the perovskite Ag3BiO3/Ti3C2 MXene plasmonic heterojunction with a self-breathing strategy, which was beneficial for developing high-performance self-powered photoelectrochemical biosensors. [ABSTRACT FROM AUTHOR]

Industrial applications of microbial electrochemical systems will require regular maintenance shutdowns, involving inspections and component replacements to extend the lifespan of the system. Here, we examined the impact of such shutdowns on the performance of three electrode materials (i. e., platinized titanium, graphite, and nickel) as cathodes in a microbial electrochemical system that would be used for electromethanogenesis in power‐to‐gas applications. We focused on methane (CH4) production from hydrogen (H2) and carbon dioxide (CO2) using Methanothermobacter thermautotrophicus. We showed that the platinized titanium cathode resulted in high volumetric CH4 production rates and Coulombic efficiencies. Using a graphite cathode would be more cost‐effective than using the platinized titanium cathode in microbial electrochemical systems, but showed an inferior performance. The microbial electrochemical system with the nickel cathode showed improvements compared to the graphite cathode. Additionally, this system with a nickel cathode demonstrated the fastest recovery during a shutdown experiment compared to the other two cathodes. Fluctuations in pH and nickel concentrations in the catholyte during power interruptions affected CH4 production recovery in the system with the nickel cathode. This research enhances understanding of the integration of biological and electrochemical processes in microbial electrochemical systems, providing insights into electrode selection and operating strategies for effective and sustainable CH4 production. [ABSTRACT FROM AUTHOR]

Interfacial electron transfer between electroactive microorganisms (EAMs) and electrodes underlies a wide range of bio‐electrochemical systems with diverse applications. However, the electron transfer rate at the biotic‐electrode interface remains low due to high transmembrane and cell‐electrode interfacial electron transfer resistance. Herein, a modular engineering strategy is adopted to construct a Shewanella oneidensis‐carbon felt biohybrid electrode decorated with bacterial cellulose aerogel‐electropolymerized anthraquinone to boost cell‐electrode interfacial electron transfer. First, a heterologous riboflavin synthesis and secretion pathway is constructed to increase flavin‐mediated transmembrane electron transfer. Second, outer membrane c‐Cyts OmcF is screened and optimized via protein engineering strategy to accelerate contacted‐based transmembrane electron transfer. Third, a S. oneidensis‐carbon felt biohybrid electrode decorated with bacterial cellulose aerogel and electropolymerized anthraquinone is constructed to boost the interfacial electron transfer. As a result, the internal resistance decreased to 42 Ω, 480.8‐fold lower than that of the wild‐type (WT) S. oneidensis MR‐1. The maximum power density reached 4286.6 ± 202.1 mW m−2, 72.8‐fold higher than that of WT. Lastly, the engineered biohybrid electrode exhibited superior abilities for bioelectricity harvest, Cr6+ reduction, and CO2 reduction. This study showed that enhancing transmembrane and cell‐electrode interfacial electron transfer is a promising way to increase the extracellular electron transfer of EAMs. [ABSTRACT FROM AUTHOR]

Sweat is considered the most promising candidate to replace conventional blood samples for noninvasive sensing. There are many tools and optical and electrochemical methods that can be used for detecting sweat biomarkers. Electrochemical methods are known for their simplicity and cost-effectiveness. However, they need to be optimized in terms of selectivity and catalytic activity. Therefore, electrode modifiers such as nanostructures and metal–organic frameworks (MOFs) or combinations of them were examined for boosting the performance of the electrochemical sensors. The MOF structures can be prepared by hydrothermal/solvothermal, sonochemical, microwave synthesis, mechanochemical, and electrochemical methods. Additionally, MOF nanostructures can be prepared by controlling the synthesis conditions or mixing bulk MOFs with nanoparticles (NPs). In this review, we spotlight the previously examined MOF-based nanostructures as well as promising ones for the electrochemical determination of sweat biomarkers. The presence of NPs strongly improves the electrical conductivity of MOF structures, which are known for their poor conductivity. Specifically, Cu-MOF and Co-MOF nanostructures were used for detecting sweat biomarkers with the lowest detection limits. Different electrochemical methods, such as amperometric, voltammetric, and photoelectrochemical, were used for monitoring the signal of sweat biomarkers. Overall, these materials are brilliant electrode modifiers for the determination of sweat biomarkers. [ABSTRACT FROM AUTHOR]

This study reports the development of an innovative electrochemical bioplatform for the indirect determination of acrylamide (AM) based on its inhibitory effect on the hybridization of nucleic acids through the formation of AM‐guanine single‐stranded (ssDNA) adducts. The method combines the advantages of the formation and selective immunorecognition of DNA/RNA heteroduplex, with the use of MBs and amperometric transduction using disposable SPCEs. Increasing concentrations of acrylamide prevented the efficient hybridization of a synthetic biotinylated DNA probe immobilized on streptavidin‐coated magnetic beads with its complementary RNA target and the as‐formed heteroduplex recognition with a specific antibody and a secondary HRP‐labeled antibody used for electrochemical readout. The resulting magnetic bioconjugates were magnetically trapped on the surface of the working electrode of a SPCE and the amperometric transduction was carried out in the presence of the H2O2/HQ system, recording a cathodic response inversely proportional to the AM concentration. The developed bioplatform is more competitive with other reported methods in terms of simplicity and assay time, allowing the selective detection of 1 nM AM in 60 min. In addition, the bioplatform was applied to the analysis of potato crisp water extracts. [ABSTRACT FROM AUTHOR]

The burgeoning intersection of machine learning (ML) with electrochemical sensing heralds a transformative era in analytical science, pushing the boundaries of what's possible in detecting and quantifying chemical substances with unprecedented precision and efficiency. This convergence has accelerated a number of discoveries, improving electrochemical sensors' sensitivity, selectivity, and ability to comprehend complicated data streams in real-time. Such advancements are crucial across various applications, from monitoring health biomarkers to detecting environmental pollutants and ensuring industrial safety. Yet, this integration is not without its challenges; it necessitates navigating intricate ethical considerations around data use, ensuring robust data privacy measures, and developing specialized software tools that balance accessibility and security. As the field progresses, addressing these challenges head-on is essential for harnessing the full potential of ML-enhanced electrochemical sensing. This review briefly explores these dimensions, spotlighting the significant technological strides, the ethical landscape, and the dynamic interplay between open-source and proprietary software solutions while also casting a forward gaze at the promising future directions of this interdisciplinary venture. [ABSTRACT FROM AUTHOR]

Paper-based rapid diagnostic tests (RDTs) are an essential component of modern healthcare, particularly for the management of infectious diseases. Despite their utility, these capillary-driven RDTs are compromised by high failure rates, primarily caused by user error. This limits their utility in complex assays that require multiple user operations. Here, we demonstrate how this issue can be directly addressed through continuous electrochemical monitoring of reagent flow inside an RDT using embedded graphenized electrodes. Our method relies on applying short voltage pulses and measuring variations in capacitive discharge currents to precisely determine the flow times of injected samples and reagents. This information is reported to the user, guiding them through the testing process, highlighting failure cases and ultimately decreasing errors. Significantly, the same electrodes can be used to quantify electrochemical signals from immunoassays, providing an integrated solution for both monitoring assays and reporting results. We demonstrate the applicability of this approach in a serology test for the detection of anti-SARS-CoV-2 IgG in clinical serum samples. This method paves the way towards "smart" RDTs able to continuously monitor the testing process and improve the robustness of point-of-care diagnostics. [ABSTRACT FROM AUTHOR]

This research introduces a novel electrochemical sensor designed for the detection of chloroquine. The sensor was developed via a simple method to synthesize TiO2 nanoparticles on reduced graphene oxide. The modified electrodes created in this manner exhibited high electrocatalytic activity and distinct chemical reactivity. Various techniques were utilized to perform morphological characterization of the nanocomposites. These techniques revealed alterations revealed changes in functional groups and the attachment of titanium to the reduced graphene oxide present on the electrode surface, thereby elucidating the reasons for the enhanced electrochemical performance. The sensor had a broad measurement range for chloroquine, capable of detecting concentrations as low as 10−8 M. It is applicable for diverse sample analyses, including water, pharmaceuticals, human urine, and serum, with satisfaction ranging between 97 and 99%. The development strategy. An electrochemical sensor was developed using titanium oxide nanoparticles attached to reduced graphene oxide TiO2-NPs @RGO/GCE for real-time detection of chloroquine in real contaminated samples such as human urine, human serum, and tap water with low detection limit. [ABSTRACT FROM AUTHOR]

A highly ultrafast and sensitive electrochemical sensor based on electrical potential-assisted hybridization was developed for the determination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The electrode was modified with multi-walled carbon nanotubes (MWCNTs) and Au nanoparticles (AuNPs) for excellent electrochemical performance. The constant electric field was applied to rapidly and efficiently enrich the capture probes to the electrode surface in 60 s. Meanwhile, pyrene as the backfill reagent resulted in a significant reduction of nonspecific adsorption. The electrochemical properties of the modified electrode were investigated via electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The analytical response was measured by differential pulse voltammetry (DPV). The sensor achieved the ultrafast hybridization of nucleic acids at the electrode interface within 90 s, substantially reducing the reaction time from hours to minutes. Under optimal conditions, the sensor exhibited a superior detection limit of 60 fM and showed satisfactory specificity toward single-base mismatch. Additionally, the proposed sensor realized sensitive determination of SARS-CoV-2 in throat swabs. The enzyme-free and non-amplification sensing strategy showed promising potential for application in point-of-care testing (POCT). [ABSTRACT FROM AUTHOR]

The marketing authorization of Advanced Therapy Medicinal Products (ATMPs) in Brazil is recent. The features of these therapies impose specialized regulatory action and are consequently challenging for developers. The goal of this study was to identify the industry's experience in clinical development, marketing authorization and access to ATMPs through the Unified Health System (SUS, acronym in Portuguese), from a regulatory perspective. A survey containing structured questions was conducted among research participants who work at companies that commercialize ATMPs. A descriptive analysis was performed. We invited 15 foreign pharmaceutical companies, of which 10 agreed to participate. Overall, participants assessed that Brazil has a well-established regulatory system, especially the sanitary registration by the National Health Surveillance Agency (Anvisa), which ensures the quality, safety, and efficacy of the products. The Agency's good interaction with the regulated sector, the harmonization of sanitary and ethical assessment systems with other countries, and the analysis time in the biosafety assessment of Genetically Modified Organisms (GMOs) stand out as positive in industry's evaluation. On the other hand, it is important to advance the pricing regulation for these products since Brazilian regulations do not establish specific criteria for ATMP. One of the biggest challenges is the difficulty for the SUS in reimbursing these very high-cost therapies, especially using current Health Technology Assessment (HTA) methods. Considering the increasing number of approvals of cell and gene therapies in Brazil in the coming years, a close dialogue between the industry and the public sector is recommended to advance regulatory improvements (pricing and HTA). Additionally, the construction of policies to promote the national Health Economic-Industrial Complex, based on a mission-oriented vision that encourages innovative models of financing, especially those that consider risk-sharing and co-financing technologies, will help provide the population with universal, equitable and sustainable access to ATMP in the SUS. [ABSTRACT FROM AUTHOR]

High power output and high conversion efficiency are crucial parameters for microbial fuel cells (MFCs). In our previous work, we worked with microfluidic MFCs to study fundamentals related to the power density of the MFCs, but nutrient consumption was limited to one side of the microchannel (the electrode layer) due to diffusion limitations. In this work, long-term experiments were conducted on a new four-electrode microfluidic MFC design, which grew Geobacter sulfurreducens biofilms on upward- and downward-facing electrodes in the microchannel. To our knowledge, this is the first study comparing electroactive biofilm (EAB) growth experiencing the influence of opposing gravitational fields. It was discovered that inoculation and growth of the EAB did not proceed as fast at the downward-facing anode, which we hypothesize to be due to gravity effects that negatively impacted bacterial settling on that surface. Rotating the device during the growth phase resulted in uniform and strong outputs from both sides, yielding individual power densities of 4.03 and 4.13 W m−2, which increased to nearly double when the top- and bottom-side electrodes were operated in parallel as a single four-electrode MFC. Similarly, acetate consumption could be doubled with the four electrodes operated in parallel. [ABSTRACT FROM AUTHOR]

Studies have used anaerobic-digester sludge and/or effluent as inocula for bioelectrochemical systems (BESs), such as microbial fuel cells (MFCs), for power generation, while limited studies have isolated and characterized electrochemically active bacteria (EAB) that inhabit anaerobic digesters. In the present work, single-chamber MFCs were operated using the anaerobic-digester effluent as the sole source of organics and microbes, and attempts were made to isolate EAB from anode biofilms in MFCs by repeated anaerobic cultivations on agar plates. Red colonies were selected from those grown on the agar plates, resulting in the isolation of three phylogenetically diverse strains affiliated with the phyla Bacillota, Campylobacterota and Deferribacterota. All these strains are capable of current generation in pure-culture BESs, while they exhibit different electrochemical properties as assessed by cyclic voltammetry. The analyses of their cell-free extracts show that cytochromes are abundantly present in their cells, suggesting their involvement in current generation. The results suggest that anaerobic digesters harbor diverse EAB, and it would be of interest to examine their ecological niches in anaerobic digestion. [ABSTRACT FROM AUTHOR]

Abstract\nHIGHLIGHTSVitamin B6 (VB6) is a member of the water-soluble B vitamins which have a vital performance in nervous system operating activities. VB6 is highly demanded to maintain excellent skin and immune systems in the human body. furthermore, VB6 is tremendously substantial in the functions of some enzymes that participate in the metabolism of proteins, amino acids, etc. The deficiency of VB6 will eventuate in anemic situations and may lead to permanent injuries in the brain. moreover, recent studies disclosed that adequate Vitamin B6 in the human body can decrease the intensity of illnesses such as diabetes, stress, etc., in patients with COVID-19 infections. Thus, the detection of VB6 from real samples is crucial to control the amount of this vitamin in biological fluids and to monitor the pharmaceutical dosage quality. Various analytical approaches have been employed for the VB6 detection in biological and pharmaceutical samples. Although biosensing and sensing approaches hold several obvious advantages such as simplicity, capability for miniaturization, quick response time, etc. from other analytical methods. Hence, through the last decades, designing and fabricating biosensors with sufficient sensitivity and selectivity have been investigated by many researchers in order to detect VB6. The purpose of this review is to illustrate the importance of diverse electrochemical and optical approaches for VB6 detection. Additionally, novel VB6 detection techniques based on electrochemical, optical, and conventional methods have been considerably discussed, and compared with each other. Furthermore, a comprehensive summary of the current limitations and future challenges in VB6 analysis are explained and also create a pathway for subsequent expansions and applications.Vitamin B6 is an essential compound for proper function of human body.Various nanomaterial-based methods such as conational approach, electrochemical biosensing and apta-sensing analyses for Vitamin B6 detection has been developed.Different techniques for detecting of Vitamin B6 have been comprehensively discussed.Various electrochemical sensors fabrication and its application in Vitamin B6 detection with nanomaterials have been assessed.The article points out the recent progress limitations, and also the upcoming tasks in the successful sensor fabrication with the functionalized nanomaterials.Vitamin B6 is an essential compound for proper function of human body.Various nanomaterial-based methods such as conational approach, electrochemical biosensing and apta-sensing analyses for Vitamin B6 detection has been developed.Different techniques for detecting of Vitamin B6 have been comprehensively discussed.Various electrochemical sensors fabrication and its application in Vitamin B6 detection with nanomaterials have been assessed.The article points out the recent progress limitations, and also the upcoming tasks in the successful sensor fabrication with the functionalized nanomaterials. [ABSTRACT FROM AUTHOR]

In this study, waste nutrient solution (WNS) was used as a catholyte in a bioelectrochemical cell to directly produce hydrogen peroxide (H2O2), after which the H2O2- containing WNS was integrated with the downstream UV oxidation process to meet quality standards for reuse. The generated current in the bioelectrochemical cell was successfully utilized at the cathode to produce H2O2 in WNS using a two-electron oxygen reduction reaction with different reaction times. The cathodic reaction time with the highest H2O2 production (504 ± 5.2 mg l−1) was 48 h, followed by that obtained from 24 h (368 ± 4.1 mg l−1), 12 h (158.8 ± 2.4 mg l−1), and 6 h (121.1 ± 4.1 mg l−1) reaction times. During H2O2 generation, calcium, magnesium, and phosphate in the WNS were recovered in the form of precipitates under alkaline conditions. The H2O2-containing WNS was further treated with different UV doses. After UV/H2O2 treatment, excitation-emission matrix and molecular weight distribution analyses demonstrated that aromatic compounds were reduced. Moreover, the gene expressions of sul1 (up to 95.65%), tetG (up to 93.88%), and aadA (up to 95.32%) were clearly downregulated compared with those of a control sample. Finally, a high disinfection efficiency was achieved with higher UV doses, resulting in successful seed germination. Thus, our results indicate that the developed method can be a promising process for reusing WNS in hydroponic systems. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) is one of the most serious non‐communicable diseases affecting the population. In the early‐stages patients have no obvious symptoms, until it becomes life‐threatening leading end‐stage kidney failure. Therefore, it is important to early diagnose CKD to allow therapeutic interventions and progression monitoring. Here, a point‐of‐care (POC) sensing platform is reported for the simultaneous detection of three CKD biomarkers, namely creatinine, urea, and human serum albumin (HSA), using reduced graphene oxide/polydopamine‐molecularly imprinted polymer (rGO/PDA‐MIP) fabricated with novel surface‐molecularly imprinting technology. A multi‐channel electrochemical POC readout system with differential pulse voltammetry (DPV) function is developed, allowing the simultaneous detection of the three biomarkers, in combination with the surface‐MIP electrodes. This sensing platform achieves the record low limit‐of‐detection (LoD) at a femtomolar level for all three analytes, with wide detection ranges covering their physiological concentrations. Clinical validation is performed by measuring these analytes in serum and urine from healthy controls and patients with CKD. The average recovery rate is 81.8–119.1% compared to the results obtained from the hospital, while this platform is more cost‐effective, user‐friendly, and requires less sample‐to‐result time, showing the potential to be deployed in resource‐limited settings for the early diagnosis and tracking progression of CKD. [ABSTRACT FROM AUTHOR]

Leukemia is one of the ten types of cancer that causes the biggest death in the world. Compared to other types of cancer, leukemia has a low life expectancy, so an early diagnosis of the cancer is necessary. A new strategy has been developed to identify various leukemia biomarkers by making blood cancer biosensors, especially by developing nanomaterial applications so that they can improve the performance of the biosensor. Although many biosensors have been developed, the detection of leukemia by using nanomaterials with electrochemical and optical methods is still less carried out compare to other types of cancer biosensors. Even the acoustic and calorimetric testing methods for the detection of leukemia by utilizing nanomaterials have not yet been carried out. Most of the reviewed works reported the use of gold nanoparticles and electrochemical characterization methods for leukemia detection with the object of study being conventional cancer cells. In order to be used clinically by the community, future research must be carried out with a lot of patient blood objects, develop non-invasive leukemia detection, and be able to detect all types of blood cancer specifically with one biosensor. This can lead to a fast and accurate diagnosis thus allowing for early treatment and easy periodic condition monitoring for various types of leukemia based on its biomarker and future design controlable via internet of things (IoT) so that why would be monitoring real times. [ABSTRACT FROM AUTHOR]

A novel scaffold for in situ electrochemical detection of cell biomarkers was developed using electrospun nanofibers and commercial adhesive polymeric membranes. The electrochemical sensing of cell biomarkers requires the cultivation of the cells on/near the (bio)sensor surface in a manner to preserve an appropriate electroactive available surface and to avoid the surface passivation and sensor damage. This can be achieved by employing biocompatible nanofiber meshes that allow the cells to have a normal behavior and do not alter the electrochemical detection. For a better mechanical stability and ease of handling, nylon 6/6 nanofibers were collected on commercial polymeric membranes, at an optimal fiber density, obtaining a double-layered platform. To demonstrate the functionality of the fabricated scaffold, the screening of cellular stress has been achieved integrating melanoma B16-F10 cells and the (bio)sensor components on the transducer whereas the melanin exocytosis was successfully quantified using a commercial electrode. Either directly on the surface of the (bio)sensor or spatially detached from it, the integration of cell cultures in biosensing platforms based on electrospun nanofibers represents a powerful bioanalytical tool able to provide real-time information about the biomarker release, enzyme activity or inhibition, and monitoring of various cellular events. [ABSTRACT FROM AUTHOR]

The conventional electrochemical detection strategy for alpha-fetoprotein (AFP) is limited by the antigen-antibody (Ag-Ab) reactions and suffers from low sensitivity and poor reproducibility due to the inconsistency of Ab-modified electrodes. Herein, we designed and explored a sandwich-type electrochemical sensor for highly sensitive detection of AFP based on aptamer (Apt)–AFP–Ab interaction mode with silver@gold (Ag@Au) core-shell nanoparticles (NPs) as a signal amplifier. AuNPs were electrodeposited onto MXene (Ti3C2TX)-modified glassy carbon electrode (GCE) to get AuNPs/MXene/GCE and further used as the signal amplification substrate. The tetrahedral DNA-linked AFP aptamers were immobilized onto AuNPs/MXene/GCE surface via Au–S bonds and used as the sensing and recognition platform for AFP capturing. Ag@AuNPs with core-shell structures were synthesized, characterized, and bound with Ab as detection elements by catalyzing H2O2 reduction. In the presence of AFP, a stable Apt–AFP–Ab sandwich structure was formed owing to the high affinities of aptamer and Ab toward the target AFP. The catalytic current produced by H2O2 reduction increased linearly with the logarithm of AFP concentration from 5 × 10−4 ng/mL to 1 × 105 ng/mL, accompanied by a low detection limit (1.6 × 10−4 ng/mL). Moreover, the novel sandwich-type electrochemical sensor shows high sensitivity, outstanding selectivity, and promising performance in the analysis of actual samples, displaying a broad application prospect in bioanalysis. [ABSTRACT FROM AUTHOR]

A sensing interface co-constructed from the two-dimensional conductive material (Ag@MXene) and an antifouling cyclic multifunctional peptide (CP) is described. While the large surface area of Ag@MXene loads more CP probes, CP binds to Ag@MXene to form a fouling barrier and ensure the structural rigidity of the targeting sequence. This strategy synergistically enhances the biosensor's sensitivity and resistance to contamination. The SPR results showed that the binding affinity of the CP to the target was 6.23 times higher than that of the antifouling straight-chain multifunctional peptide (SP) to the target. In the 10 mg/mL BSA electrochemical fouling test, the fouling resistance of Ag@MXene + CP (composite sensing interface of CP combined with Ag@MXene) was 30 times higher than that of the bare electrode. The designed electrochemical sensor exhibited good selectivity and wide dynamic response range at PD-L1 concentrations from 0.1 to 50 ng/mL. The lowest detection limit was 24.54 pg/mL (S/N = 3). Antifouling 2D materials with a substantial specific surface area, coupled with non-straight chain antifouling multifunctional peptides, offer a wide scope for investigating the sensitivity and antifouling properties of electrochemical sensors. [ABSTRACT FROM AUTHOR]

The development of an ultrasensitive and precise measurement of a breast cancer biomarker (cancer antigen 15-3; CA15-3) in complex human serum is essential for the early diagnosis of cancer in groups of healthy populations and the treatment of patients. However, currently available testing technologies suffer from insufficient sensitivity toward CA15-3, which severely limits early large-scale screening of breast cancer patients. We report a versatile electrochemical immunoassay method based on atomically cobalt-dispersed nitrogen-doped carbon (Co-NC)–modified disposable screen-printed carbon electrode (SPCE) with alkaline phosphatase (ALP) and its metabolite, ascorbic acid 2-phosphate (AAP), as the electrochemical labeling and redox signaling unit for sensitive detection of low-abundance CA15-3. During electrochemical detection by differential pulse voltammetry (DPV), it was found that the Co-NC-SPCE electrode did not have a current signal response to the AAP substrate; however, it had an extremely favorable response current to ascorbic acid (AA). Based on the above principle, the target CA15-3-triggered immunoassay enriched ALP-catalyzed AAP produces a large amount of AA, resulting in a significant change in the system current signal, thereby realizing the highly sensitive detection of CA15-3. Under the optimal AAP substrate concentration and ALP catalysis time, the Co-NC-SPCE-based electrochemical immunoassay demonstrated a good DPV current for CA15-3 in the assay interval of 1.0 mU/mL to 10,000 mU/mL, with a calculated limit of detection of 0.38 mU/mL. Since Co-NC-SPCE has an excellent DPV current response to AA and employs split-type scheme, the constructed electrochemical immunoassay has the merits of high preciseness and anti-interference, and its clinical diagnostic results are comparable to those of commercial kits. [ABSTRACT FROM AUTHOR]

An efficient electrochemical transducer matrix for immunosensing must possess a variety of specialized characteristics, comprised of stability, quick electron transport, biocompatibility, having a large electroactive surface area, and exhibiting certain functional groups, to facilitate biomolecule attachment. For sensitive detection of CA 15-3 and to provide higher electroactive surface area, CS–ZnO–CeO2 nanocomposites were synthesized to modify the electrode surface and characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The immunosensor shows a sensitive response with a sensitivity of 15.79 µAmUmL−1 and a linear range of 0.1–20 mUmL−1 with 1.24 mUmL−1 limit of detection (LOD) (S/N = 3) for CA 15-3 detection. The immunosensor developed as a result was utilized to detect CA 15-3 in human serum samples without any pretreatment, only dilution, and recovery rates ranging from 91 to 95%. As a result, the immunosensor displays the proper fabrication of the electrochemical biosensors to detect the CA 15-3 in actual sample analysis and exhibits excellent stability, sensitivity, repeatability, and reproducibility. [ABSTRACT FROM AUTHOR]

Lead is a highly toxic metal associated with many human health diseases that can be caused by several environmental changes. Innovative sustainable solutions for water remediation have been recently encouraged by using renewable, low-cost and earth-abundant biomass materials to ensure public health conditions. In this article, Cereus jamacaru DC (popularly known as Mandacaru) was investigated as a biosorbent in the Pb2+ removal from aqueous solution using a two-level factorial design. The analysis of variance suggested a significant and predictive model (R2 = 0.9037). The maximum efficacy of Pb2+ removal in the experimental design was 97.26%, being the optimized conditions: pH 5.0, contact time 4 h without adding NaCl. The Mandacaru was divided into three types according to the plant structure and this parameter did not present a significant interference in the biosorption process. This result corroborates with slight differences in the total soluble proteins, carbohydrates and phenolic compounds found in the Mandacaru types investigated. FT-IR analysis revealed the presence of O–H, C–O and C = O groups that were responsible for the ion biosorption process. The optimized procedure was capable to remove 97.28% of the Pb2+ added in the Taborda river water sample. The kinetic adsorption results show the pseudo-second-order model, suggesting chemisorption process. Thus the treated water sample can be considered in accordance with technical standards issued by CONAMA Resolution Num. 430/2011 and Ordinance GM/MS Num.888/2021 of WHO. In this way, the Mandacaru proved to be an efficient, fast and easy-to-apply bioadsorbent in Pb2+ removal and has great environmental application potential. [ABSTRACT FROM AUTHOR]

The treatment of agroindustrial wastewater using microbial fuel cells (MFCs) is a technological strategy to harness its chemical energy while simultaneously purifying the water. This manuscript investigates the organic load effect as chemical oxygen demand (COD) on the production of electricity during the treatment of cassava wastewater by means of a dual-chamber microbial fuel cell in batch mode. Additionally, specific conditions were selected to evaluate the semi-continuous operational mode. The dynamics of microbial communities on the graphite anode were also investigated. The maximum power density delivered by the batch MFC (656.4 μW m - 2 ) was achieved at the highest evaluated organic load (6.8 g COD L - 1 ). Similarly, the largest COD removal efficiency (61.9%) was reached at the lowest organic load (1.17 g COD L - 1 ). Cyanide degradation percentages (50–70%) were achieved across treatments. The semi-continuous operation of the MFC for 2 months revealed that the voltage across the cell is dependent on the supply or suspension of the organic load feed. The electrode polarization resistance was observed to decreases over time, possibly due to the enrichment of the anode with electrogenic microbial communities. A metataxonomic analysis revealed a significant increase in bacteria from the phylum Firmicutes, primarily of the genus Enterococcus. [ABSTRACT FROM AUTHOR]

Simultaneous measurements of various molecules ("multiplex") using electrochemical biosensors typically require multiple electrode implementations, which for neonates, hemophiliacs, etc. is problematic. Here, we introduce the oxazine ATTO 700 into electrochemical aptamer-based biosensors to achieve "true" multiplex, continuous and real-time measurements of two different molecules in undiluted whole blood using a single electrode. [ABSTRACT FROM AUTHOR]

Earlier access to patients' biomarker status could transform disease management. However, gold-standard techniques such as enzyme-linked immunosorbent assays (ELISAs) are typically not deployed at the point-of-care due to their cumbersome instrumentation and complexity. Electrochemical immunosensors can be disruptive in this sector with their small size and lower cost but, without further modifications, the performance of these sensors in complex media (e.g., blood) has been limited. This paper presents a low-cost fluidic accessory fabricated using widely accessible materials and processes for boosting sensor sensitivity through confinement of the detection media next to the electrode surface. Liquid confinement first highlighted a spontaneous reaction between the pseudoreference electrode and ELISA detection substrate 3,3',5,5'-tetramethylbenzidine (TMB) that decreases the amount of oxTMB available for detection. Different strategies are investigated to limit this and maximize reliability. Next, flow cell integration during the signal amplification step of sensor preparation was shown to substantially enhance the detection of cytokine interleukin-6 (IL-6) with the best sensitivity boost recorded for fresh human plasma (x7 increase compared to x5.8 in purified serum and x5.5 in PBS). The flow cell requires no specialized equipment and can be seamlessly integrated with commercial sensors, making an ideal companion for electrochemical signal enhancement. [ABSTRACT FROM AUTHOR]

This study introduces a novel label-free immunosensor that has the potential to be utilized for clinical screening and diagnosis of prostate cancer. The electrochemical immunosensor's performance was enhanced by combining 3,4-ethylenedioxythiophene (EDOT), 3-methylthiophene (3MT), and gold nanoparticles (AuNPs), enabling the accurate and sensitive determination of serum prostate specific antigen (PSA) concentrations. The immunosensor platform used [Fe(CN)6]3−/4− as a redox probe to obtain the signal, and the DPV technique was used to correlate the signal with the PSA concentration. The linear range of AuNPs/p(EDOT-co-3MT)/PGE is 0.1 to 50 000 pg mL−1, with a detection limit of 0.083 pg mL−1. In interference studies with interferences such as bovine serum albumin, carcinoembryonic antigen, uric acid, ascorbic acid, vitamin B12, vitamin B9, L -tyrozine, L -phenylalanine, Cu2+, Fe2+, and Zn2+ the immunosensor showed excellent anti-interference properties. The designed sensor platform is facile, inexpensive, highly sensitive, and selective, and has a high surface area, excellent electrical conductivity, and biocompatibility. Furthermore, this technology is highly suitable for industrial-scale production and can be easily converted into point-of-care detection devices due to its low cost, reproducibility, selectivity, and accuracy. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the bioflocculant chitosan and its nano-conjugated form in biofloc production and to evaluate the growth performance of genetically improved farmed tilapia (GIFT) in an insitu biofloc system. A completely randomised design (CRD) was used to evaluate the growth performance of GIFT in insitu biofloc over a 75-day period. The trial was conducted with biofloc control (T1), 30 ppm chitosan (T2) and 30 ppm nano-chitosan (T3) in triplicate. The water quality parameters were maintained in the optimum range for biofloc production. The highest value for flocculation activity, total suspended solids, total dissolved solids and total solids other than floc volume was observed in T3 followed by T2 and T1. The result of this study showed that there was a significant difference (p < 0.05) between treatments in terms of specific growth rate (SGR), weight gain (%WG), feed conversion ratio (FCR), feed efficiency ratio (FER) and daily increment (DI). Good growth performance of fish was observed in biofloc produced with nano-chitosan in terms of average body weight (g) (24.74 ± 2.58), SGR (%/day) (3.56 ± 0.094), PWG (%) (1546.27 ± 143.42), lowest FCR (1.421 ± 0.029), FER (0.62 ± 0.011), PER (1.68 ± 0.03) and DI (g day−1) (0.21 ± 0.014). The highest levels of amylase, lipase and protease activity and increased activity of antioxidant enzymes (SOD and CAT) were found in the T3 treatment compared to T2 and T1 treatments. This study demonstrated that biofloc developed with 30 ppm nano-chitosan could shorten the production time of biofloc, maintain the water quality of the biofloc system and improve the growth of GIFT tilapia reared in an insitu biofloc system with inland saline groundwater. [ABSTRACT FROM AUTHOR]

Cerebrospinal fluid (CSF) is a body fluid that can be used for the diagnosis of various diseases. However, CSF collection requires an invasive and painful procedure called a lumbar puncture (LP). This procedure is applied to any patient with a known risk of central nervous system (CNS) damage or neurodegenerative disease, regardless of their age range. Hence, this can be a very painful procedure, especially in infants and elderly patients. On the other hand, the detection of disease biomarkers in CSF makes diagnoses as accurate as possible. This review aims to explore novel electrochemical biosensing platforms that have impacted biomedical science. Biosensors have emerged as techniques to accelerate the detection of known biomarkers in body fluids such as CSF. Biosensors can be designed and modified in various ways and shapes according to their ultimate applications to detect and quantify biomarkers of interest. This process can also significantly influence the detection and diagnosis of CSF. Hence, it is important to understand the role of this technology in the rapidly progressing field of biomedical science. [ABSTRACT FROM AUTHOR]

The rapid detection of the spore form of Clostridioides difficile has remained a challenge for clinicians. To address this, we have developed a novel, precise, microwave-enhanced approach for near-spontaneous release of DNA from C. difficile spores via a bespoke microwave lysis platform. C. difficile spores were microwave-irradiated for 5 s in a pulsed microwave electric field at 2.45 GHz to lyse the spore and bacteria in each sample, which was then added to a screen-printed electrode and electrochemical DNA biosensor assay system to identify presence of the pathogen's two toxin genes. The microwave lysis method released both single-stranded and double-stranded genome DNA from the bacterium at quantifiable concentrations between 0.02 μg/mL to 250 μg/mL allowing for subsequent downstream detection in the biosensor. The electrochemical bench-top system comprises of oligonucleotide probes specific to conserved regions within tcdA and tcdB toxin genes of C. difficile and was able to detect 800 spores of C. difficile within 300 µL of unprocessed human stool samples in under 10 min. These results demonstrate the feasibility of using a solid-state power generated, pulsed microwave electric field to lyse and release DNA from human stool infected with C. difficile spores. This rapid microwave lysis method enhanced the rapidity of subsequent electrochemical detection in the development of a rapid point-of-care biosensor platform for C. difficile. [ABSTRACT FROM AUTHOR]

Early diagnosis of hepatocellular carcinoma (HCC), a leading cause of cancer mortality, is decisive for successful treatment of this type of cancer and increasing the patients' survival rate. Alpha-fetoprotein (AFP) is a glycoprotein that has been currently employed as a potential serological biomarker for determination of HCC and several other cancers. Achieving highly sensitive and specific detection of this biomarker is an effective strategy to inhibit developing issues caused by the cancer. Though, traditional procedures cannot meet the requirements due to the technical drawbacks. Recently, growing number of aptamer-based biosensors (aptasensors) attracted important attention as superior diagnostic tools because of their unique properties such as high stability, target versatility and remarkable affinity and selectivity. Nanomaterials, which broadly employed in the structure of these aptasensors, can considerably enhance the detection limit and sensitivity of analytes determination. Therefore, this review selectively investigated the recent progresses in several different optical and electrochemical aptasensors and nano-aptasensors designed for AFP assay. [ABSTRACT FROM AUTHOR]

Precise and sensitive bioanalysis has been the major and urgent pursuit in pathologic diagnosis, food safety, environment monitoring, and drug evaluation. Photoelectrochemical (PEC) bioanalysis, as one of the most promising detection technologies, has rapidly expanded within the field of analysis. However, most of reported PEC analysis approaches still suffer from weak external anti-interference ability, high background, and the risk of false positive or negative errors due to their inherent single-signal readout. To overcome these shortcomings, new PEC-coupled dual-modal analysis approaches have been developed, where a dual-response signal can be derived through two completely different mechanisms and independent signal transduction pathways. This review introduces the basic principles of PEC biosensing and enumerates and classifies the substrate or probe selections, constructions, and applications of PEC-coupled dual-modal biosensors. Furthermore, the challenges and developmental prospects of PEC-coupled dual-mode sensing technologies are evaluated and discussed. We hope that this review will provide valuable insights into the latest advancements and practical applications of dual-mode PEC bioanalysis, which will be of great interest to those seeking to stay informed in this field. [ABSTRACT FROM AUTHOR]

The transition to a circular economy entails new challenges for architects and designers. Among these, one challenge is to look at waste not only as new resources, from an environmental perspective, but also as bearers of information capable of communicating their history and origin. Moreover, waste can be considered as a means of activating unexpected knowledge and social connections. The article illustrates a circular design experimentation, conducted with architecture and design students and a wine farm, which led to the creation of the CiaBOT project, a belvedere aimed at enhancing the landscape and providing a temporary stopping point in the Monferrato hills (UNESCO World Heritage Site, Italy). CiaBOT is not only a belvedere but is a microarchitecture capable of conveying both material and immaterial cultural values. Its form and materials are intimately connected with the territory with and for which it was designed. These make CiaBOT a "space" of hybridization and dialogue between agricultural tradition and innovation. But it is also a "space" of fieldwork education and knowledge co-generation in which academic and non-academic stakeholders have measured themselves. Through the description of the different stages of the design process, the article is part of the debate on new sustainable ways of designing and building, reflecting on new models of circular economy based as much on design strategies and processes as on the enhancement of human labor and the use of technologies appropriate to the context and actors. [ABSTRACT FROM AUTHOR]

Invasive intracranial electrodes are used in both clinical and research applications for recording and stimulation of brain tissue, providing essential data in acute and chronic contexts. The impedance characteristics of the electrode–tissue interface (ETI) evolve over time and can change dramatically relative to pre-implantation baseline. Understanding how ETI properties contribute to the recording and stimulation characteristics of an electrode can provide valuable insights for users who often do not have access to complex impedance characterizations of their devices. In contrast to the typical method of characterizing electrical impedance at a single frequency, we demonstrate a method for using electrochemical impedance spectroscopy (EIS) to investigate complex characteristics of the ETI of several commonly used acute and chronic electrodes. We also describe precise modeling strategies for verifying the accuracy of our instrumentation and understanding device–solution interactions, both in vivo and in vitro. Included with this publication is a dataset containing both in vitro and in vivo device characterizations, as well as some examples of modeling and error structure analysis results. These data can be used for more detailed interpretation of neural recordings performed on common electrode types, providing a more complete picture of their properties than is often available to users. Dataset: Data discussed here can be found on the Dryad repository at the following link: https://doi.org/10.5061/dryad.8931zcrvw , accessed on 9 April 2024. Dataset License: The dataset is published under a CC0 license. [ABSTRACT FROM AUTHOR]

Exploring alternative energy sources is vital amid increasing human fuel consumption. Globally, biogas, rich in methane, hydrogen sulfide, and carbon dioxide, addresses energy demands through biomass anaerobic digestion (AD). Efficient digestate management, employing techniques like solid‐liquid separation and composting, is crucial for environmental protection. The goal is to optimize nutrient‐rich byproduct utilization while minimizing negative impacts. This review analyzes diverse substrates, emphasizing challenges and benefits. Key considerations include nutrient ratios, moisture content, co‐digestion, organic loading rate, and retention time. The study explores temperature's impact on microbial growth, biogas impurities, and upgradation techniques, including biological methods. Fermentation, microbial electrochemical techniques, and biochar use for enhanced AD are introduced. Discussing digestate's multifaceted aspects, the review highlights its nutrient value and diverse applications in aquaculture, animal feed, fermentation, bioremediation, and fine chemical production. [ABSTRACT FROM AUTHOR]

Abstract Industrial applications of microbial electrochemical systems will require regular maintenance shutdowns, involving inspections and component replacements to extend the lifespan of the system. Here, we examined the impact of such shutdowns on the performance of three electrode materials (i. e., platinized titanium, graphite, and nickel) as cathodes in a microbial electrochemical system that would be used for electromethanogenesis in power‐to‐gas applications. We focused on methane (CH4) production from hydrogen (H2) and carbon dioxide (CO2) using Methanothermobacter thermautotrophicus. We showed that the platinized titanium cathode resulted in high volumetric CH4 production rates and Coulombic efficiencies. Using a graphite cathode would be more cost‐effective than using the platinized titanium cathode in microbial electrochemical systems, but showed an inferior performance. The microbial electrochemical system with the nickel cathode showed improvements compared to the graphite cathode. Additionally, this system with a nickel cathode demonstrated the fastest recovery during a shutdown experiment compared to the other two cathodes. Fluctuations in pH and nickel concentrations in the catholyte during power interruptions affected CH4 production recovery in the system with the nickel cathode. This research enhances understanding of the integration of biological and electrochemical processes in microbial electrochemical systems, providing insights into electrode selection and operating strategies for effective and sustainable CH4 production.

Biotechnology has limited effectiveness in terms of removing mixed antibiotics at low temperatures, leading to ecological risks arising from the presence of antibiotics in environmental waters. In this study, the removal of tetracycline (TCs) and sulfonamide (SAs) from antibiotic wastewater was improved by the intermittent electrical stimulation of anaerobic-aerobic-coupled upflow bioelectrochemical reactors (AO-UBERs) at low temperatures. The removal effects of oxytetracycline and tetracycline were 48.6 ± 3.5 % and 71.5 ± 2.9 %, respectively. Under 0.9V, the removal rates of oxytetracycline, tetracycline, and trimethoprim were significantly increased in both the aerobic-cathodic and anaerobic anodic chambers, with a more obvious increase at low temperatures. Compared with the blank control group, the removal efficiency of oxytetracycline, trimethoprim and tetracycline in the electric group was increased by 11.8 ± 2.5 %, 27.8 ± 10.5 % and 11.2 ± 5.8 %. The anaerobic chamber contributed more to the removal of TCs and trimethoprim than the aerobic chamber. Furthermore, electrical stimulation selectively enriched electroactive bacteria (Methylophage and Pleuromonas), drug-resistant bacteria (Proteobacteria), and nitrifying bacteria associated with biodegradation. The abundance of antibiotic-resistance genes is related to the distribution of potential hosts and mobile genetic elements (sul1), and electrical stimulation induces the enrichment of both. This suggests that while potentially effective for treating TCs- and SAs-containing wastewater at low temperatures, AO-UBERs may lead to the accumulation of antibiotic-resistance genes.

Designing high efficiency platinum (Pt)‐based catalysts for methanol oxidation reaction (MOR) with high "non‐CO" pathway selectivity is strongly desired and remains a grand challenge. Herein, PtRuNiCoFeGaPbW HEA ultrathin nanowires (HEA‐8 UNWs) are synthesized, featuring unique cascaded p–d orbital hybridization interaction by inducing dual p‐block metals (Ga and Pb). In comparison with Pt/C, HEA‐8 UNWs exhibit 15.0‐ and 4.2‐times promotion of specific and mass activity for MOR. More importantly, electrochemical in situ FITR spectroscopy reveals that the production/adsorption of CO (CO*) intermediate is effectively avoided on HEA‐8 UNWs, leading to the complete "non‐CO" pathway for MOR. Theoretical calculations demonstrate the optimized electronic structure of HEA‐8 UNWs can facilitates a lower energy barrier for the "non‐CO" pathway in the MOR. [ABSTRACT FROM AUTHOR]

Recent advancements in wearable technology have led to a new era of intelligent wound dressings capable of monitoring vital healing biomarkers. While a significant leap from traditional gauze dressings, these innovations still necessitate periodic removal and disposal. Bioresorbable electrochemical sensors have emerged as a promising and sustainable solution, offering continuous monitoring of critical wound healing biomarkers in real‐time and in situ, followed by their full physiological resorption. The current challenge lies in the susceptibility of metallic electrodes to harsh electrolytic biofluids, hindering the development of viable transient electrochemical sensors. This study pioneers a bioresorbable electrochemical material and unique architecture comprising engineered sputtered tungsten (W) plus tungsten oxide (WOx) thin films, taking advantage of their high catalytic activity and uniquely gradual biodissolution. While a bare W film electrode detached from the wafer substrate within 5 hours of soaking, an annealed W‐WOx electrode showcases a notable electrochemical stability at body temperature, for up to several days. The latter reliably senses multiple analytes during 24‐hour room‐temperature tests. These findings underscore the potential of annealed W plus WOx electrodes in future bioresorbable wound management systems. [ABSTRACT FROM AUTHOR]

The inorganic content and the catalytic performance pose metal‐loaded enzyme nanoflowers as promising candidates for developing bioelectrodes capable of functioning without the external addition of a redox mediator. However, these protein‐inorganic hybrids have yet to be successfully applied in combination with electrode materials. Herein, the synthesis procedure of these bionanomaterials is reproposed to precisely control the morphology, composition, and performance of this particular protein‐mineral hybrid, formed by glucose oxidase and cobalt phosphate. This approach aims to enhance the adherence and electron mobility between the enzyme and a carbon electrode. The strategy relies on dressing the protein in a tailored thin nanogel with multivalent chemical motifs. The functional groups of the polymer facilitate the fast protein sequence‐independent biomineralization. Furthermore, the engineered enzymes enable the fabrication of robust cobalt‐loaded enzyme inorganic hybrids with exceptional protein loads, exceeding 90% immobilization yields. Notably, these engineered biohybrids can be readily deposited onto flat electrode surfaces without requiring chemical pre‐treatment. The resulting bioelectrodes are robust and exhibit electrochemical responses even without the addition of a redox mediator, suggesting that cobalt complexes promote electron wiring between the active site of the enzyme and the electrode. [ABSTRACT FROM AUTHOR]

Impact electrochemistry allows for the investigation of the properties of single entities, ranging from nanoparticles (NPs) to soft bio-particles. It has introduced a novel dimension in the field of biological analysis, enhancing researchers' ability to comprehend biological heterogeneity and offering a new avenue for developing novel diagnostic devices for quantifying biological analytes. This review aims to summarize the recent advancements in impact electrochemistry-based biosensing over the past two to three years and provide insights into the future directions of this field. [ABSTRACT FROM AUTHOR]

Thermoelectrics have great potential for use in waste heat recovery to improve energy utilization. Moreover, serving as a solid-state heat pump, they have found practical application in cooling electronic products. Nevertheless, the scarcity of commercial Bi2Te3 raw materials has impeded the sustainable and widespread application of thermoelectric technology. In this study, we developed a low-cost and earth-abundant PbS compound with impressive thermoelectric performance. The optimized n-type PbS material achieved a record-high room temperature ZT of 0.64 in this system. Additionally, the first thermoelectric cooling device based on n-type PbS was fabricated, which exhibits a remarkable cooling temperature difference of ~36.9 K at room temperature. Meanwhile, the power generation efficiency of a single-leg device employing our n-type PbS material reaches ~8%, showing significant potential in harvesting waste heat into valuable electrical power. This study demonstrates the feasibility of sustainable n-type PbS as a viable alternative to commercial Bi2Te3, thereby extending the application of thermoelectrics. The authors fabricate a thermoelectric cooling device based on n-type PbS based material, which exhibits a remarkable cooling temperature difference of 36.9 K at room temperature, and the single-leg power generation efficiency of 8%. [ABSTRACT FROM AUTHOR]

In the realm of microfluidics, a critical issue prevails: The commercially available flow sensors are situated external to the microfluidic chip, resulting in an inherent deficiency of precise operational insights. Applications such as biochemistry, drug development, single cell analyses, gradient generators, biomedical devices and proactive healthcare demand dependable data for broader utilization. In the present work, we introduce a microfluidic flow sensor designed to gauge electrolyte flow rates on-chip inside a microchannel by measuring electrochemical resistance of electrolytic bubbles within a circuit comprising electrolytic fluid and inter-digitated electrodes. This sensor design features a Si wafer substrate with micropatterned Ti/Pt electrodes bonded to a polydimethylsiloxane (PDMS) microchannel using oxygen plasma. The sensor has been characterized for electrolytic fluid (0.1 M NaCl), 600 μ m wide microchannel, 0–500 μ l/min range of flow, 3V dc power input, and 25 ∘ C room temperature conditions. Sensor response has been compared for electrolyte concentrations (0.1 M to 0.4 M NaCl), channel width (400–1200 μ m), and input power (1–5 V) corresponding to a given flow rate. The sensor 3 σ resolution calculated from calibration curve is observed to be 5 μ l/min for lower flow rates (0–100 μ l/min) and 100 μ l/min for higher flow rates (100–500 μ l/min). The limit of detection (LoD) of the sensor is 1 μ l/min. An algorithm based on the trapezoidal rule enabling flow rate prediction within 5 s has been implemented. The proposed flow sensor works over a broad range of flow rates, although with different sensitivity, presenting a novel method employing the electrolysis bubble size and volume for flow rate detection. [ABSTRACT FROM AUTHOR]

To accurately detect tumor marker carbohydrate antigen 72-4 (CA72-4) of serum samples is of great significance for the early diagnosis of malignant tumors. In the present study, MnO2/hollow nanobox metal-organic framework (HNM)-AuPtPd nanocomposites were prepared via multi-step synthesis and superposition method and a series of characterizations were carried out. A highly sensitive immunosensor Ab/MnO2/HNM-AuPtPd/GCE based on the composite nanomaterial was further prepared and used to detect the tumor marker CA72-4. The constructed immunosensor achieved signal amplification by increasing the electrocatalytic activity to H2O2 by means of the synergistic effect of MnO2 ultra-thin nanosheets (MnO2 UNs) and HNM-AuPtPd. At the same time, the electrochemical properties of the immunosensor were analyzed using cyclic voltammetry, electrochemical impedance, amperometry (with the test voltage of −0.4 V), and differential pulse voltammetry. The experimental results showed that the MnO2/HNM-AuPtPd nanocomposites were successfully prepared, and the immunosensor Ab/MnO2/HNM-AuPtPd/GCE demonstrated an excellent electrochemical performance. The electrochemical immunosensor had the highest detection sensitivity under the optimal experimental conditions, such as incubation pH of 7.0, incubation time of 60 min, with the addition of 15 μL of H2O2, and in the concentration range 0.001–500 U/mL. It had a low detection limit of 1.78×10−5 U/mL (S/N = 3). Moreover, the serum sample recovery were in the range from 99.38 to 100.52%. This study provides a new method and experimental basis for the detection of tumor markers in clinical practice. [ABSTRACT FROM AUTHOR]

The development of bioelectrochemical systems requires careful selection of both their biotic and abiotic components to obtain sustainable devices. Herein, we report a biophotoelectrode obtained with polyhydroxybutyrate (PHB), a biopolymer, which purple non-sulphur bacteria produce as an energy stock under specific environmental conditions. The electrode was obtained by casting a mixture composed of PHB and carbon fibers in a 3:2 mass ratio. Following, the composite material was modified with polydopamine and thermally treated to obtain a hydrophilic electrode with improved electrochemical behavior. The bio-based electrode was tested with metabolically active cells of Rhodobacter capsulatus embedded in a biohybrid matrix of polydopamine. The system achieved enhanced catalytic activity under illumination, with an 18-fold increase in photocurrent production compared to biophotoelectrodes based on glassy carbon, reaching a current density of 12 ± 3 μ A cm−2, after 30 min of light exposure at +0.32 V. The presented biocompatible electrode provides a sustainable alternative to metal-based and critical raw material-based electrodes for bioelectrochemical systems. [ABSTRACT FROM AUTHOR]

Hydrogen plays a pivotal role in the decarbonization of the fuel industry as both an energy vector and a chemical, however most of the available technologies still heavily rely on fossil fuels and sustainable processes are still unused due to their higher operational costs. MECs are devices based on the utilization of electroactive microorganisms that can interact with polarized electrodes (usually graphite-based), using them as the final electron acceptor for their metabolism. The use of a bioanode capable of oxidizing the organic substances contained in wastewater makes it possible to utilize part of the chemical energy present in the reduced waste compounds for the generation of green hydrogen, reducing the required (theoretical) potential by 85% compared to conventional electrolysis (+1.23 V vs +0.187 V). This study aims to compare two different polarization strategies of a microbial electrolysis cell aimed at hydrogen production coupled with the oxidation of synthetic wastewater. The study clearly showed the advantage of using potentiostatic polarization over galvanostatic polarization due to lower energy consumption during the potentiostatic polarization mode. Indeed, galvanostatic polarization promoted the loss of biological activity due to kinetic limitations in the biological reactions. Consequently, water oxidation on graphite granules occurred in the anodic chamber, increasing the anodic potential up to 0.95 V vs. SHE. [ABSTRACT FROM AUTHOR]

This project aimed to explore the influence of the interaction between ovotransferrin fibrils (OTF) and gum arabic (GA) on the formation mechanism, physicochemical properties, and curcumin delivery of the oleogel-in-water Pickering emulsion. Cryo-scanning electron microscopy results showed that OTF—GA complexes effectively adsorbed on the oil–water interface, generating spatial hindrance to inhibit droplet coalescence. The texture analysis also proved that OTF—GA complexes endowed oleogel-in-water Pickering emulsion with preferable springiness (0.49 ± 0.03 mm), chewiness (0.43 ± 0.07 mJ), and adhesion (0.31 ± 0.01 mJ). By exploring the coalescence stability, droplet size, and rheological properties of OTF—GA complexes–stabilized oleogel-in-water Pickering emulsion (OGPE), the higher coagulation stability, larger average droplet size (46.22 ± 0.08 μm), and stronger gel strength were observed. The microrheological results also exhibited stronger attraction between the OGPE droplets, a more pronounced solid-like structure, and a slower speed of movement than OTF-stabilized oleogel-in-water Pickering emulsion (OPE). Meanwhile, OGPE significantly enhanced the extent of lipolysis, stability, and bioaccessibility of curcumin, suggesting that it possessed superior performance as a delivery system for bioactive substances. This project provided adequate theoretical references for protein–polysaccharide complexes–stabilized oleogel-in-water Pickering emulsion, and contributed to expanding the application of oleogel-in-water Pickering emulsion in the food industry. [ABSTRACT FROM AUTHOR]

Electroporation is pivotal in bioelectrochemistry for cellular manipulation, with prominent applications in drug delivery and cell membrane studies. A comprehensive understanding of pore generation requires an in-depth analysis of the critical pore size and the corresponding energy barrier at the onset of cell rupture. However, many studies have been limited to basic models such as artificial membranes or theoretical simulations. Challenging this paradigm, our study pioneers using a microfluidic electroporation chip array. This tool subjects live breast cancer cell species to a diverse spectrum of alternating current electric field conditions, driving electroporation-induced cell rupture. We conclusively determined the rupture voltages across varying applied voltage loading rates, enabling an unprecedented characterization of electric cell rupture dynamics encompassing critical pore radius and energy barrier. Further bolstering our investigation, we probed cells subjected to cholesterol depletion via methyl-β-cyclodextrin and revealed a strong correlation with electroporation. This work not only elucidates the dynamics of electric rupture in live cell membranes but also sets a robust foundation for future explorations into the mechanisms and energetics of live cell electroporation. [ABSTRACT FROM AUTHOR]

A cold cathode plasma source is constructed for modifying PTFE surface characteristics. The source was easily built, had a consistent plasma discharge medium and acceleration system. A cylindrical Langmuir probe is also used to evaluate plasma parameters like density, temperature or even plasma potential. This probe is designed to be moveable so that it may approach any desired position in the plasma volume. The influences of nitrogen pressure and probe-cathode gap on plasma parameters were investigated. The electron temperature T e fluctuated from 7. 7 3 × 1 0 4 to 6. 8 × 1 0 4 eV as the pressure rises from 0.2 to 0.4 mbar. Further, by increasing the cathode-probe gap from 0.4 to 2 cm, the electron densities increased from 0. 4 6 × 1 0 1 0 cm − 3 to 0. 8 9 × 1 0 1 0 cm − 3 . Furthermore, the contact angles, work of adhesion and surface free-energy of pristine as well as irradiated PTFE films, were estimated. The results demonstrated that by extending the plasma exposure duration from 0 to 12 min, the water contact angle is lowered from 82.2∘ to 30.5∘. At these conditions, the work of adhesion is raised from 81.9 to 134.1 mJ/m2, as the surface free energy is increased from 29.8 to 71.8 mJ/m2. [ABSTRACT FROM AUTHOR]