Rapid Capture Research Articles

Directional anchoring of polymer-lysozyme nanohybrids for adhesive capture and enhanced removal of Alicyclobacillus acidoterrestris in fruit juices

The acidophilic and heat-resistant traits of Alicyclobacillus acidoterrestris (A. acidoterrestris) present a formidable challenge to fruit juices production safety. To address the limitations of conventional thermal sterilization, a novel bacterial capture device MPDEL has been developed. This innovative device utilizes dopamine-coated magnetic nanoparticles that are covalently linked with lysozyme, enabling efficient and rapid capture of A. acidoterrestris in acidic juices, followed by facile magnetic-controlled separation for subsequent removal. Lysozyme not only recognizes and directional anchors the bacterial surface, but facilitates the adhesion of polydopamine to the bacterial surface. Benefiting from the abundant binding sites and rapid adsorption kinetics, this un-thermal treatment completely removes 104 CFU/mL of A. acidoterrestris from the juice within a span of 20 min. The MPDEL exhibits high capture performance, negligible cytotoxicity and no discernable impact on juice quality, offering a novel option for the removal of A. acidoterrestris from fruit juices.

Prolonging Charge Carrier Lifetime via Intraband Defect Levels in S-Scheme Heterojunctions for Artificial Photosynthesis.

S-scheme heterostructure photocatalysts, distinguished by unique charge-transfer pathways and exceptional catalytic redox capabilities, have found widespread applications in addressing challenging chemical processes, including the photocatalytic reduction of CO2 with a high reaction barrier. Nevertheless, the influence of intraband defect levels within S-scheme heterojunctions on charge separation, carrier lifetime, and surface catalytic reactions has, for the most part, been overlooked. Herein, we develop a tunable defect-level-assisted strategy to construct an electron reservoir, effectively prolonging the lifetime of charge carriers through the rapid capture and gradual release of photoelectrons within WO3-x/In2S3 S-scheme heterojunctions, as authenticated by femtosecond transient absorption spectroscopy and theoretical simulations. The surface photoredox mechanism, unraveled by Gibbs free energy calculations, demonstrates that oxygen-vacancy-induced defect states in WO3-x/In2S3 heterojunctions unlock the rate-determining H2O oxidation into free oxygen molecules by forming metastable oxygen intermediates, contributing to the facilitation of H2O photooxidation. This distinct role, combined with the extended carrier lifetime, results in boosted CO2 photoreduction with nearly 100 % CO selectivity in the absence of any photosensitizer or scavenger. Our work sheds light on the role of controllable defect levels in governing charge transfer dynamics within S-scheme heterojunctions, thereby inspiring the development of more advanced photocatalysts for artificial photosynthesis.

Coaxially Bi/ZnO@ZnSe Array Photocathode Enables Highly Efficient CO2 to C1 Conversion via Long-lived High-energy Photoelectrons.

The key aspect of the photoelectrochemical CO2 reduction reaction (PEC CO2 RR) lies in designing cathode materials that can generate high-energy photoelectrons, enabling the activation and conversion of CO2 into high-value products. In this study, a coaxially wrapped ZnO@ZnSe array heterostructure was synthesized using a simple anion exchange strategy and metallic Bi nanoparticles (NPs) were subsequently deposited on the surface to construct a Bi/ZnO@ZnSe photocathode with high CO2 conversion capability. This array photocathode possesses a large aspect ratio, which simultaneously satisfies a low charge carrier migration path and a large specific surface area that facilitates mass transfer. Additionally, the barrier formed at the n-n heterojunction interface hinders the transfer of high-energy photoelectrons from ZnSe to lower energy levels, resulting in their rapid capture by Bi while maintaining a relatively long lifetime. These captured electrons act as active sites, efficiently converting CO2 into CO with a Faradaic efficiency above 88.9 % at -0.9 V vs. RHE and demonstrating superior stability. This work provides a novel approach for synthesizing high-energy photoelectrode materials with long lifetimes.

A range of voltage-clamp protocol designs for rapid capture of hERG kinetics

We provide details of a series of short voltage-clamp protocols designed for gathering a large amount of information on hERG (Kv11.1) ion channel gating. The protocols have a limited number of steps and consist only of steps and ramps, making them easy to implement on any patch clamp setup, including automated platforms. The primary objective is to assist with parameterisation, selection and refinement of mathematical models of hERG gating. We detail a series of manual and automated model-driven designs, together with an explanation of their rationale and design criteria. Although the protocols are intended to study hERG1a currents, the approaches could be easily extended and generalised to other ion channel currents.

Vibrational Relaxation Completes the Excitation Energy Transfer and Localization of Vibronic Excitons in Allophycocyanin α84-β84.

Phycobilisomes are light-harvesting complexes that play a key role in photosynthesis in cyanobacteria, which generate more than 40% of the world's oxygen. The near-unity excitation energy transfer efficiency from phycobilisomes to photosystems highlights its importance in understanding efficient energy transfer processes. Spectroscopic studies have shown that the 280 fs rapid excitonic downhill energy transfer within the α84-β84 chromophore dimer in allophycocyanin (APC), a subunit of phycobilisomes, is crucial to this efficiency. However, the role of strong chromophore-protein interactions and vibrational relaxation requires further exploration to fully explain this efficient downhill energy transfer. A theory is required that adequately describes exciton dynamics in an intermediate region while also incorporating vibrational relaxation mediated by protein bath modes. In this work, we incorporate vibrational relaxation into modified Redfield theory by introducing coupling fluctuation. We holistically simulate the rapid excitation energy transfer process of the α84-β84 chromophore dimer in APC and successfully model the recently observed rapid energy capture. We find that vibrational relaxation dictates capture of excitons by the localized state of the β84 chromophore. The calculated rate shows excellent agreement with previous ultrafast spectroscopic experiments. Our results show that the inclusion of vibrational relaxation is essential for systems that utilize vibronic coupling to enhance energy transfer and capture. Consequently, incorporating vibrational relaxation into Modified Redfield theory shows promise for accurately describing the excitation energy transfer process in other photosynthetic systems.

Recyclable Robust Plastic Scintillation Resin Achieving the Exceptional Separation and Detection of Technetium-99.

Rapid detection and absorption of 99TcO4 ⁻ contamination in the environment are critical due to its high radioactivity, long half-life, and significant environmental mobility. Resins have been demonstrated effective bifunctional properties for both the detection and separation of 99TcO4 ⁻. However, the poor stability of these compounds limits their practical application. Here, a chemical grafting strategy is presented to synthesize ultra-stable plastic scintillation resin, in which 4-vinylpyridine and divinylbenzene are cross-linked as matrix polymer to withstand extreme conditions and a fluorophore "shield" to convert beta radiation into detectable signals. As expected, the as-obtained resin exhibits a high adsorption capacity of 549.2 mg g⁻¹ for 99TcO4 ⁻ with a rapid kinetic response of just 10 min as well as superior selectivity at 1000 times excess of interfering ions and full reusability. Moreover, it showed remarkable stability under 800 kGy, 3.0 mol L-1 HNO3 or 2.5 L solution continuous leaching, consistently maintaining high separation and detection efficiency after recycling 10 times. This strategy paves a new way to develop stable resin for the rapid capture and accurate measurement of 99TcO4 ⁻, which owns great potential for practical application.

Rapid Capture Perfluorooctanoic Acid and Perfluorooctane Sulfonate at Environmentally Relevant Concentrations via the ‘mesh trap’ of Triazine-Based Polymer Network: Mechanism and Photocatalytic regeneration

Per- and polyfluoroalkyl substances (PFAS) pose a serious threat to groundwater (GW) environment worldwide due to their difficulty in removal and high toxicity. In this study, the ‘mesh trap’ of triazine-based polymerization network (SNW-1) demonstrated rapid capture performance for Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) at environmentally relevant concentrations (1μg/L). The SNW-1 can remove more than 90% of PFOA and PFOS within 300s and still maintain superior performance under four common GW anions and different [pH]0 (3 - 10). The removal degree of PFOA and PFOS is almost undetectable without SNW-1 dosage. Theoretical calculations were used to simulate the adsorption process and interfacial reaction mechanism in SNW-1/PFOA (Eads = -1.6717eV) and SNW-1/PFOS (Eads = -1.2695eV) systems. The adsorption of SNW-1/PFOA is stronger than SNW-1/PFOS. The typical van der Waals weak interactions between SNW-1 and PFOA were confirmed, which is slightly stronger than SNW-1/PFOS. In addition, SNW-1 regeneration in this paper was achieved in a photocatalytic activated peroxydisulfate (PDS) system which was different with previous reports. The desorption rates of PFOA and PFOS adsorbed on the surface of SNW-1 and the defluorination rate in the photocatalytic regeneration system were also tested. The photocatalytic regeneration mechanism between SNW-1 and PDS was electron transfer. And the electron transfer can be divided into three stages: strong adsorption of SNW-1/PDS (Eads = -2.1618eV), electron transfer from SNW-1 to PDS and PDS cleavage. This study has a broad application prospect in the field of in-situ rapid resistance control of GW in PFAS contaminated sites and provides a theoretical support for environmentally friendly adsorbent regeneration technology.

Acoustic pipette and biofunctional elastomeric microparticle system for rapid picomolar-level biomolecule detection in whole blood.

Most biosensing techniques require complex processing steps that generate prolonged workflows and introduce potential points of error. Here, we report an acoustic pipette to purify and label biomarkers in 70 minutes. A key aspect of this technology is the use of functional negative acoustic contrast particles (fNACPs), which display biorecognition motifs for the specific capture of biomarkers from whole blood. Because of their large size and compressibility, the fNACPs robustly trap along the pressure antinodes of a standing wave and separate from blood components in under 60 seconds with >99% efficiency. fNACPs are subsequently fluorescently labeled in the pipette and are analyzed by both a custom, portable fluorimeter and flow cytometer. We demonstrate the detection of anti-ovalbumin antibodies from blood at picomolar levels (35 to 60 pM) with integrated controls showing minimal nonspecific adsorption. Overall, this system offers a simple and versatile approach for the rapid, sensitive, and specific capture of biomolecules.

Paper Spray Ionization Mass Spectrometry Coupled with Paper-Based Three-Dimensional Tumor Model for Rapid Metabolic Gradient Profiling.

The tumor microenvironment (TME), especially with its complicated metabolic characteristics, will dynamically affect the proliferation, migration, and drug response of tumor cells. Rapid metabolic analysis brings out a deeper understanding of the TME, while the susceptibility and environmental dependence of metabolites extremely hinder real-time metabolic profiling since the TME is easily disrupted. Here, we directly integrated paper spray ionization mass spectrometry with a paper-based three-dimensional (3D) tumor model, realizing the rapid capture of metabolic gradients. The entire procedure, from sample preparation to mass spectrometry detection, took less than 4 min, which was able to provide metabolic results close to real time and contributed to understanding the real metabolic processes. At present, our method successfully detected 160 metabolites; notably, over 40 significantly gradient metabolites were revealed across the six layers of the paper-based 3D tumor model. At least 22 gradient metabolites were reported to be associated with cell viability. This strategy was powerful enough to rapidly profile metabolic gradients of a paper-based 3D tumor model for revealing cell viability changes from a metabolomics perspective.

Specific isolation and quantification of PD-L1 positive tumor derived exosomes for accurate breast cancer discrimination via aptamer-functionalized magnetic composites and SERS immunoassay

PD-L1 positive tumor derived exosomes (TEXsPD−L1) play a significant role in disease progression, tumor metastasis and cancer immunotherapy. However, the overlap of PD-L1 between TEXs and non-tumor derived exosomes (non-TEXs) restricts the specific isolation and quantification of TEXPD−L1 from clinical samples. Herein, a new aptamer-functionalized and hydrophilic immunomagnetic substrate was designed by decorating generation 5 polyamidoamine dendrimers (G5 PAMAM), zwitterionic trimethylamine N-oxide (TMAO) and EpCAM (Epithelial cell adhesion molecule) aptamers on magnetic cores sequentially (Fe3O4@PAMAM@TMAO@Aptamer, named as FPTA) for rapid target and efficient capture of TEXs. The FPTA substrate gathered excellent characters of strong magnetic responsiveness of Fe3O4, abundant affinity sites of PAMAM, strong hydrophilicity of TMAO and enhanced affinity properties of EpCAM aptamers. Because of these advantages, FPTA can isolate TEXs quickly within 30min with high capture efficiency of 90.5 % ± 3.0 % and low nonspecific absorption of 8.2 % ± 2.0 % for non-TEXs. Furthermore, PD-L1 (Programmed cell death-ligand 1) positive TEXs (TEXsPD−L1) from the captured TEXs were recognized and quantitatively analyzed by utilizing SERS (surface-enhanced Raman spectroscopy) reporter molecules 4-NTP (4-Nitrothiophenol) on PD-L1 aptamers-functionalized gold immunoaffinity probe. The signal of TEXsPD−L1 was converted to SERS signal of 4-NTP at 1344 cm−1 which exhibited a linear correlation to concentration of TEXsPD−L1(R2 = 0.9905). With these merits, this strategy was further applied to clinical plasma samples from breast cancer (BC) patients and healthy controls (HC), exhibited an excellent diagnosis accuracy with area under curve (AUC) of receiver operating characteristic (ROC) curve reaching 0.988. All these results demonstrate that the FPTA immunomagnetic substrate combined with SERS immunoaffinity probe may become a generic tool for specific isolation and quantitative analysis of PD-L1 positive tumor-derived exosomes in clinics.

Rapid and efficient carbon dioxide capture through benzene-1,4-diamine based hierarchical porous hyper-cross-linked polymers

Carbon dioxide (CO2) emission causes global warming which has been the greatest challenge for humanity since last decade. Herein, we developed nitrogen and phosphorus rich hyper cross-linked polymers for CO2 capture, designated as BDA-HCP-1 and BDA-HCP-2 (benzene-1,4-diamine based hyper cross-linked polymers) having BET surface area 294.5904 m2g-1 and 519.6918 m2g-1 respectively. The pore width range of BDA-HCP-1 and BDA-HCP-2 is 0–25 nm and 0–15 nm and pore volume of BDA-HCP-1 and BDA-HCP-2 is 0.01–0.18cm3/g and 0.01–0.25 cm3/g, respectively.Total pore volume, studied using DFT, is 0.20100 cm3/g for BDA-HCP-1 and 0.27973 cm3/g for BDA-HCP-2. BJH cumulative pore volume of BDA-HCP-1 is 0.113023 cm3/g and BDA-HCP-2 is 0.284733 cm3/g. The BDA-HCP-1and BDA-HCP-2 were synthesized by replacement of chlorines of hexachlorocyclophosphazenes (HCCP) and phosphorousdichlorophosphazenes (PDCP) with bezene-1,4-diamine to form linear and cyclic polyphosphazenes, which are later cross-linked through Friedal crafts reaction to form hyper cross-linked polymers. The maximum CO2 adsorption quantity of BDA-HCP-1 is 48.62 cm3/g (CO2 weight adsorbed 9.070 % with equilibrium time 8.16 min) at 273K/1 bar and 37.96 cm3/g (weight adsorbed 7.15 % with equilibrium time 8.25 min) at 298K/1 bar that gives adsorption capacity of 2.14 mmol/g and 1.69 mmol/g, respectively. Adsorption capacity of BDA-HCP-2 is 2.30 mmol/g and 2.13 mmol/g at 273 K/1 bar and 298 K/1 bar respectively. It is calculated from maximum CO2 adsorption quantity of 51.6 cm3/g (weight adsorbed 9.83 % with equilibrium time 11.4 min, at 273 K/1 bar) and 47.7 cm3/g (weight adsorbed 9.25 % with equilibrium time 8.45 min, at 298 K/1 bar) respectively. Both BDA-HCPs can be reused with minor loss in adsorption capacity (2 and 1 %), which makes them excellent candidates to use on industrial scale applications. Adsorption isotherm study (Langmuir, Freundlich, and Temkin) and Kinetics study (pseudo first order and pseudo second order) reveals that this study fit best for Freundlich isotherms and pseudo first order kinetic model for both BDA-HCPs. This research contributes valuable insights into the design of hyper cross-linked materials with high surface area, good pore volume, excellent thermal stability and promising gas adsorption capacities particularly for addressing environmental pollution challenges related to CO2 emissions.

Laboratory Tests of Metrological Characteristics of a Non-Repetitive Low-Cost Mobile Handheld Laser Scanner.

The popularity of mobile laser scanning systems as a surveying tool is growing among construction contractors, architects, land surveyors, and urban planners. The user-friendliness and rapid capture of precise and complete data on places and objects make them serious competitors for traditional surveying approaches. Considering the low cost and constantly improving availability of Mobile Laser Scanning (MLS), mainly handheld surveying tools, the measurement possibilities seem unlimited. We conducted a comprehensive investigation into the quality and accuracy of a point cloud generated by a recently marketed low-cost mobile surveying system, the MandEye MLS. The purpose of the study is to conduct exhaustive laboratory tests to determine the actual metrological characteristics of the device. The test facility was the surveying laboratory of the University of Agriculture in Kraków. The results of the MLS measurements (dynamic and static) were juxtaposed with a reference base, a geometric system of reference points in the laboratory, and in relation to a reference point cloud from a higher-class laser scanner: Leica ScanStation P40 TLS. The Authors verified the geometry of the point cloud, technical parameters, and data structure, as well as whether it can be used for surveying and mapping objects by assessing the point cloud density, noise and measurement errors, and detectability of objects in the cloud.

Oxygen-Binding Sites of Enriched Gold Nanoclusters for Capturing Mitochondrial Reverse Electrons.

Reverse electron transfer (RET), an abnormal backward flow of electrons from complexes III/IV to II/I of mitochondria, causes the overproduction of a reduced-type CoQ to boost downstream production of mitochondrial superoxide anions that leads to ischemia-reperfusion injury (IRI) to organs. Herein, we studied low-coordinated gold nanoclusters (AuNCs) with abundant oxygen-binding sites to form an electron-demanding trapper that allowed rapid capture of electrons to compensate for the CoQ/CoQH2 imbalance during RET. The AuNCs were composed of only eight gold atoms that formed a Cs-symmetrical configuration with all gold atoms exposed on the edge site. The geometry and atomic configuration enhance oxygen intercalation to attain a d-band electron deficiency in frontier orbitals, forming an unusually high oxidation state for rapid mitochondrial reverse electron capture under a transient imbalance of CoQ/CoQH2 redox cycles. Using hepatic IRI cells/animals, we corroborated that the CoQ-like AuNCs prevent inflammation and liver damage from IRI via recovery of the mitochondrial function.

A Visual Distance-Based Capillary Immunoassay Using Biomimetic Polymer Nanoparticles for Highly Sensitive and Specific C-Reactive Protein Quantification.

The low-cost daily monitoring of C-reactive protein (CRP) levels is crucial for screening acute inflammation or infections as well as managing chronic inflammatory diseases. In this study, we synthesized novel 2-Methacryloyloxy ethyl phosphorylcholine (MPC)-based biomimetic nanoparticles with a large surface area to develop a visual CRP-quantification assay using affordable glass capillaries. The PMPC nanoparticles, synthesized via reflux precipitation polymerization, demonstrated multivalent binding capabilities, enabling rapid and specific CRP capture. In the presence of CRP, PMPC nanoparticles formed sandwich structures with magnetic nanoparticles functionalized with CRP antibodies, thereby enhancing detection sensitivity and specificity. These sandwich complexes were magnetically accumulated into visible and quantifiable stacks within the glass capillaries, allowing for the rapid, sensitive, and specific quantification of CRP concentrations with a detection limit of 57.5 pg/mL and a range spanning from 0 to 5000 ng/mL. The proposed visual distance-based capillary biosensor shows great potential in routine clinical diagnosis as well as point-of-care testing (POCT) in resource-limited settings.

Integration of multiscale fusion of residual neural network with 2-D gramian angular fields for lower limb movement recognition based on multi-channel sEMG signals

The human lower limb movements recognition (LLMR) plays a pivotal role in active lower limb exoskeleton robots. Employing surface electromyography (sEMG) signals for LLMR allows for the convenient, rapid and stable capture of signal variations, facilitating efficient identification of lower limb motion patterns. However, current sEMG-based LLMR methods face challenges such as incomplete feature extraction, limited contextual information and restricted feature extraction scales during feature extraction. This paper proposed a LLMR method based on Gramian Angular Fields (GAF) and multiscale fusion of Residual Neural Network (MS-ResNet). The denoised sEMG time series was transformed into Gramian Angular Difference Field (GADF) matrix based on GAF. The MS-ResNet model, incorporating ResNet and multiscale feature fusion concepts, was proposed to comprehensively capture global and local information through different-scale feature extraction and fusion, so as to improve recognition performance. sEMG signals from 11 muscles of the preferred leg of 15 healthy subjects were recorded during six common lower limb movements. Experimental analysis investigated the impact of the convolutional kernel size (k × k) in Stream 2 of MS-ResNet and the number of muscles involved on recognition performance. The study revealed that selecting k as 13, coupled with 11 muscles, yielded optimal model performance with the average cross-individual recognition accuracy reaching 97.62 %, demonstrating the model’s efficiency in LLMR. This method could provide a viable solution for developing more efficient and reliable LLMR systems, applicable to lower limb exoskeleton robots and intelligent prosthetics.

In-situ co-growth of ZIF-8-derived bio-carbon spheres with meso-macroporous hierarchy for stable and rapid carbon dioxide capture

Efficient carbon dioxide (CO2) capture from post-combustion flue gases is crucial for industrial applications. Adsorbents with high adsorption capacity, exceptional stability, high selectivity, and low cost are essential to meet these requirements. In this study, we present the synthesis of bio‑carbon spheres derived from zeolitic imidazolate framework-8 (ZIF-8) using a macro-fluidic technique. The bio‑carbon spheres integrate ZIF-8 for structural orientation and chitosan for the directional assembly of ZIF-8, thereby addressing the limitations of low strength in chitosan-derived carbon spheres and the challenge of macroscopic shaping of ZIF-8 particles. Additionally, the incorporation of ZIF-8 and the enhancement of the carbon skeleton increased the meso-macroporosity, improving CO2 transport and adsorption performance. The bio‑carbon spheres demonstrated a 46.9% higher CO2 adsorption capacity (101 kPa, 1.40 mmol·g−1) compared to pure chitosan carbon granules (101 kPa, 0.96 mmol·g−1) and a 17.8% faster mass transport rate compared to ZIF-8 carbon particles. Moreover, the bio‑carbon spheres exhibit a low wear rate in a simulated fluidized bed, good thermal stability, and stable cyclic regeneration performance. This study offers a novel strategy for developing industrially applicable adsorbents with hierarchical pore structures to enhance CO2 capture.

An NMR immunosensor based on streptavidin-biotin signal amplification for rapid detection of Salmonella in milk

Sensitive and accurate detection of harmful pathogenic bacteria in food is of great significance to public health. In this paper, a nuclear magnetic resonance (NMR) sensor based on biological signal amplification was constructed. The carboxymethyl dextran (CMD) was used as both the probe skeleton and the chelating agent to realize the fast chelating adsorption of the signal source gadolinium ion. Finally, the magnetic complex and biotinylated antibody formed an immune probe through the biological bridge to achieve rapid capture of Salmonella. In addition, non-target bacteria such as Proteus vulgaris and Listeria monocytogenes were used to test the specificity of the constructed sensor. The sensor can detect Salmonella within 1.5 h under optimal conditions, the detection limit in milk is 7.4 × 103 CFU mL−1, and the RSD (Relative standard deviation) of reproducibility experiment is 2.35%, which has good reproducibility.

Rapid oxygen atom capture on perovskite surface boosting the activity and durability of cathode for solid oxide fuel cells

The content and distribution of surface oxygen vacancies are crucial for the oxygen reduction reaction (ORR) activity of solid oxide fuel cell (SOFC) cathodes. Therefore, a facile and rapid oxygen atom capture strategy is developed to modulate the surface oxygen vacancies of the cathode. By controlling the duration of NaBH4 solution reduction, precise modulation of the surface oxygen vacancies of NdBa0.5Sr0.5Co2O5+δ (NBSC) is achieved. Consequently, the processes of oxygen adsorption, dissociation, and diffusion on the surface of the NBSC cathode are enhanced. The research findings demonstrate that NBSC reduced for 10 min (RE-NBSC-10) exhibits optimal ORR catalytic activity and CO2 tolerance. At 800 °C, the Rp of RE-NBSC-10 decreases by 45 %, reaching 0.006 Ω‧cm2. Moreover, the maximum power density (MPD) of the RE-NBSC-10 cathode reaches 1.16 W cm−2, representing a 90.2 % improvement compared to NBSC. This research provides an efficient approach for the advancement of materials tailored for next-generation energy conversion devices.

Stable and reusable calcium-responsive biopolymer for affinity precipitation of therapeutic antibodies.

Affinity precipitation is an attractive method for protein purification due to its many advantages, including the rapid capture of target proteins, simple processing, high specificity, and ease of scale-up. We previously reported a robust antibody purification method using Ca2+-dependent precipitation of ZZ-hCSQ2, a fusion protein of human calsequestrin 2, and the antibody-binding protein ZZ. However, the stability of this fusion protein was not sufficiently high for industrial use because the antibody recovery yield decreased to 60% after being reused 10 times. To identify a more stable calsequestrin (CSQ), we calculated Rosetta energy values for the folding stabilities of various CSQ homologs and selected human CSQ1 (hCSQ1) with lowest energy value (-992.6) as the new CSQ platform. We also identified that the linker sequence between ZZ and CSQ was vulnerable to proteases and alkaline pH by N-terminal protein sequencing. Therefore, we changed the linker to four asparagine (4N) sequences, which were shorter and less flexible than the previous glycine-rich linker. The new version of ZZ-CSQ, ZZ-4N-hCSQ1, was stable in a protease-containing conditioned medium obtained from the cultured Chinese hamster ovary cell or high pH condition (0.1M sodium hydroxide) for more than 5 days and could be reused at least 25 times for antibody purification without loss of recovery yield. The antibodies purified by ZZ-4N-hCSQ1 precipitation also showed greater purity (~33.6-fold lower host cell DNA and ~6.4-fold lower host cell protein) than those purified by protein A chromatography. These data suggest that ZZ-4N-hCSQ1 precipitation is more efficient and can achieve cost-effectiveness of up to 12.5-fold cheaper than previous antibody purification methods and can lower the production costs of therapeutic antibodies.

Application of MOF Nanoenzyme in Rapid Detection of Food Allergens System

Food allergies are a common immune response that can lead to serious health problems. Rapid and accurate detection of allergens in food is crucial for protecting people’s health and quality of life. In this study, β-lactoglobulin in milk serves as a model allergen, and nucleic acid aptamer-loaded MN patches are utilized as rapid capture elements. Moreover, metal organic frameworks loaded with complementary aptamer sequences are employed as signal amplification elements. The combination of these two elements establishes a rapid visualization detection system for allergens, employing specific microneedle array patches-MOF nanoenzymes. The results show that the combination of TMB+H2O2 +MOF-RC has the highest peroxidase like activity of 1.732. Compared to TMB+H2O2 +MOF, it has increased by 0.547. Meanwhile, the MN-MOF detection method has excellent specificity for the detection of β-Lg. This specific microneedle array patches and MOF nanoenzymes-based allergen rapid detection system demonstrates practical application benefits, providing a viable solution for swiftly detecting food allergens and safeguarding people’s health and quality of life.