Pyrococcus furiosus Argonaute biosensing platform based on Hemin@ZIF-90 nanozyme-modulated signal amplification for sensitive detection of Salmonella typhimurium.

Anode-Driven Controlled Release of Cathodic Fuel via pH Response for Smart Enzymatic Biofuel Cell.

The latest pandemic resulting from the novel SARS-CoV-2 coronavirus has significantly affected public health, the worldwide economy, and social life. Metal organic frameworks (MOFs) are currently being implemented in biosensors for rapid and accurate detection of viruses thanks to their exceptional properties. This research aims to develop a Zeolitic Imidazolate Framework-8 (ZIF-8) based fluorescent biosensor for facile and rapid COVID-19 RNA sequence detection. ZIF-8 was characterized using several tests, such as FT-IR, TGA, and PXRD, to examine the MOF’s crystalline structure and thermal stability. The results demonstrated high crystallinity and thermal stability up to a temperature of 550 °C. The experimental study showed that ZIF-8 is an excellent fluorescence quencher, with 78.39% quenching efficiency. Analyzing the adsorption mechanism of probe DNA into ZIF-8 revealed that they can form electrostatic and π–π stacking interactions, forming a P-DNA@ZIF-8 complex and that PET is more dominant than FRET in the quenching mechanism. This ZIF-8 biosensing platform showed high sensitivity towards COVID-19 RNA with an ultra-low limit of detection of 6.24 pM, a rapid detection time of 8 min, and high selectivity to COVID-19 RNA. Indeed, ZIF-8 experienced much lower fluorescence recovery when tested on two mismatched RNAs. The experimental results show the potential use of ZIF-8 as a novel biosensor for a rapid and sensitive COVID-19 diagnosis.

IntroductionSeveral Proficiency Test (PT) or External Quality Assessment (EQA) schemes are currently available for assessing the ability of laboratories to detect and characterize enteropathogenic bacteria, but they are usually targeting one sector, covering either public health, food safety or animal health. In addition to sector-specific PTs/EQAs for detection, cross-sectoral panels would be useful for assessment of the capacity to detect and characterize foodborne pathogens in a One Health (OH) perspective and further improving food safety and interpretation of cross-sectoral surveillance data. The aims of the study were to assess the cross-sectoral capability of European public health, animal health and food safety laboratories to detect, characterize and notify findings of the foodborne pathogens Campylobacter spp., Salmonella spp. and Yersinia enterocolitica, and to develop recommendations for future cross-sectoral PTs and EQAs within OH. The PT/EQA scheme developed within this study consisted of a test panel of five samples, designed to represent a theoretical outbreak scenario.MethodsA total of 15 laboratories from animal health, public health and food safety sectors were enrolled in eight countries: Denmark, France, Italy, the Netherlands, Poland, Spain, Sweden, and the United Kingdom. The laboratories analyzed the samples according to the methods used in the laboratory and reported the target organisms at species level, and if applicable, serovar for Salmonella and bioserotype for Yersinia.ResultsAll 15 laboratories analyzed the samples for Salmonella, 13 for Campylobacter and 11 for Yersinia. Analytical errors were predominately false negative results. One sample (S. Stockholm and Y. enterocolitica O:3/BT4) with lower concentrations of target organisms was especially challenging, resulting in six out of seven false negative results. These findings were associated with laboratories using smaller sample sizes and not using enrichment methods. Detection of Salmonella was most commonly mandatory to notify within the three sectors in the eight countries participating in the pilot whereas findings of Campylobacter and Y. enterocolitica were notifiable from human samples, but less commonly from animal and food samples.DiscussionThe results of the pilot PT/EQA conducted in this study confirmed the possibility to apply a cross-sectoral approach for assessment of the joint OH capacity to detect and characterize foodborne pathogens.

Lamellar Enzyme-Metal–Organic Framework Composites Enable Catalysis on Large Substrates

Preventive Strategy Against Infectious Diarrhea—A Holistic Approach

Hydrogen energy is regarded as one of the cleanest and most promising renewable energy sources today. Green hydrogen production from water electrolysis combine with renewable energy is the most promising approach to zero-carbon emission. The key to the success of water electrolysis technology lies in the development of efficient and low-cost catalysts. This study uses Metal-Organic Frameworks (MOFs) as catalysts, combined with photocatalysis principles, to design and prepare a highly active, easy-to-manufacture and non-precious metal photocatalytic water electrolysis bifunctional catalysts.Photocatalytic titanium dioxide (TiO₂) catalyst, fascinating absorb light energy, is synthesized by hydrothermal and followed by calcination method with titanium butoxide as precursor. TiO₂ was then combined with MOFs using a hydrothermal method to prepare a highly active photo-assisted catalyst, namely ZIF-67@TiO₂. The MOF material was based on ZIF-67 (Zeolitic Imidazolate Framework), with cobalt as the metal node and 2-methylimidazole (2-MeIm) as the organic ligand. To further improve catalytic efficiency, a phosphorus precursor was added during growth of the MOF in the hydrothermal process, the synthesized catalyst namely ZIF-67/P@TiO₂.Raman analysis revealed characteristic peaks corresponding to the vibrations of cobalt and the organic ligand 2-methylimidazole in ZIF-67, confirming the successful synthesis of the MOF structure. Additionally, Raman spectra showed the vibration peaks of anatase-phase titanium dioxide, further confirming the successful combination of TiO₂ with ZIF-67. Fourier transform infrared spectroscopy (FTIR) analysis showed that titanium dioxide (anatase) was successfully prepared. After phosphating treatment, ZIF-67, an absorption peak appears in the 1200~1300 cm-1 region, corresponding to the bonding of phosphorus and oxygen, indicating that P-O bonds are formed during the phosphating process. In addition, an absorption peak appears in the 2300-2400cm-1 region, which corresponds to the bonding of phosphorus and hydrogen, indicating the formation of P-H bonds. These peaks confirm thatphosphorus is successfully doped into ZIF-67. The X-ray photoelectron spectroscopy (XPS) analysis shows that ZIF-67 undergoes phosphating treatment after adding phosphorus precursor, and the overall peak position shifts to a low energy direction. This is due to the low electronegativity of phosphorus during the phosphating process, which causes cobalt to gain electrons, resulting in increase of electron density, which in turn reduces the bonding energy. In addition, the phosphating process will reduce part of the cobalt and convert it into metallic cobalt (Co0), which significantly enhances the intensity of the metallic cobalt peak located near 100 eV, further proving the impact of phosphating on the structure and chemical form of the material. XPS analysis of the P 2p core level also shows characteristic peaks of hypophosphite and bonding peaks of phosphorus and oxygen.A sunlight-rich environment was simulated, and continuous light was applied during electrochemical measurements to investigate the effect of sunlight on the overall hydrogen production efficiency of the catalysts. In terms of electrochemical performance, the TiO₂ catalyst showed poor electrocatalytic activity, with voltage vs current of 1.88@10mAcm⁻², 2.08@50mAcm⁻², and 2.20@100mAcm⁻². However, due to its photocatalytic activity, it significantly improved electrochemical activity when exposed to light, resulting in voltage vs current of 1.85@10mAcm⁻², 2.05@50mAcm⁻², and 2.17@100mAcm⁻². After incorporating the ZIF-67 material, the overall catalytic efficiency was improved, achieving voltage vs current of 1.80@10mAcm⁻², 1.90@50mAcm⁻², and 2.01@100mAcm⁻² when both current and light were applied simultaneously. Finally, to further enhance its overall efficiency, phosphorus precursor was added during the preparation of ZIF-67, resulting in voltage values of 1.75@10mAcm⁻², 1.86@50mAcm⁻², and 1.92@100mAcm⁻². The results show that under light assistance, the overall required voltage is effectively reduced, while the relative hydrogen production rate is enhanced. This approach makes full use of sunlight resources, reducing energy consumption and efficiently utilizing excess energy, thereby achieving energy sustainability.In summary, through structural analysis of a series of non-precious metal bifunctional MOF catalysts, we successfully synthesized highly active, long-lasting, non-precious metal bifunctional photocatalytic electrolytic catalysts using an environmentally friendly two-step hydrothermal method. Figure 1

The Economics of Enteric Infections: Human Foodborne Disease Costs

Nanotechnology-leveraged nucleic acid amplification for foodborne pathogen detection

Zeolitic imidazolate frameworks-based flame retardants for polymeric materials

Biomimic nanozymes coassembled by peptides or proteins and small active molecules provide an effective strategy to design attractive nanozymes. Although some promising nanozymes have been reported, rational regulation for higher catalytic activity of biomimic nanozymes remains challenging. Hence, we proposed a novel biomimic nanozyme by encapsulating the coassembly of hemin/bovine serum albumin (BSA) in zeolite imidazolate frameworks (ZIF-8) to achieve controllable tailoring of peroxidase-like activity via the confinement effect. The assembly of Hemin@BSA was inspired by the structure of horseradish peroxidase (HRP), in which hemin served as the active cofactor surrounded by BSA as a blocking pocket to construct a favorable hydrophobic space for substrate enrichment. Benefiting from the confinement effect, ZIF-8 with a porous intracavity was identified as the ideal outer layer for Hemin@BSA to accelerate substrate transport and achieve internal circulation of peroxidase-like catalysis, significantly enhancing its peroxidase-like activity. Especially, the precise encapsulation of Hemin@BSA in ZIF-8 could also prevent it from decomposition in harsh environments by rapid crystallization around Hemin@BSA to form a protective shell. Based on the improved peroxidase-like activity of Hemin@BSA@ZIF-8, several applications were successfully performed for the sensitive detection of small molecules including H2O2, glucose, and bisphenol A (BPA). Satisfactory results highlight that using a ZIF-8 outer layer to encapsulate Hemin@BSA offers a very effective and successful strategy to improve the peroxidase-like activity and the stability of biomimic nanozymes, broadening the potential application of biocatalytic metal-organic frameworks (MOFs).

Contaminated fresh produce remains a prominent catalyst for food-borne illnesses, prompting the need for swift and precise pathogen detection to mitigate health risks. This paper introduces an innovative strategy for identifying food-borne pathogens in fresh produce samples from local markets and grocery stores, utilizing optical sensing and machine learning. The core of our approach is a photonics-based sensor system, which instantaneously generates optical signals to detect pathogen presence. Machine learning algorithms process the copious sensor data to predict contamination probabilities in real time. Our study reveals compelling results, affirming the efficacy of our method in identifying prevalent food-borne pathogens, including Escherichia coli (E. coli) and Salmonella enteric, across diverse fresh produce samples. The outcomes underline our approach's precision, achieving detection accuracies of up to 95%, surpassing traditional, time-consuming, and less accurate methods. Our method's key advantages encompass real-time capabilities, heightened accuracy, and cost-effectiveness, facilitating its adoption by both food industry stakeholders and regulatory bodies for quality assurance and safety oversight. Implementation holds the potential to elevate food safety and reduce wastage. Our research signifies a substantial stride toward the development of a dependable, real-time food safety monitoring system for fresh produce. Future research endeavors will be dedicated to optimizing system performance, crafting portable field sensors, and broadening pathogen detection capabilities. This novel approach promises substantial enhancements in food safety and public health.

Zeolitic Imidazole Framework-67 (ZIF-67) as a heterogeneous catalyst to activate peroxymonosulfate for degradation of Rhodamine B in water

Zeolite imidazolate framework 8 (ZIF-8), which is a special subgroup of metal-organic frameworks (MOFs), has gained more interest due to its desirable characteristics. ZIF-8 was synthesized at room temperature to prepare an efficient adsorbent. The synthesized ZIF-8 was characterized by X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, field emission scanning electron microscopy (FESEM), and Brunauer–Emmett–Teller (BET) surface area analysis. This adsorbent was employed for the preconcentration of trace amounts of Cd (II) and Co (II) ions in soil, vegetable juice, and water samples with vortex-assisted dispersive solid phase microextraction (DSPME) before their identification by flame atomic absorption spectroscopy (FAAS). The experimental data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin Radushkevich (D-R) isotherm models. The monolayer adsorption capacity of ZIF-8 was found to be 238.10 mg g−1 and 90.90 mg g−1 for Cd (II) and Co (II) ions, respectively. The kinetics of the adsorption were tested using pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. The results showed that the adsorption of Cd (II) and Co(II) ions onto ZIF-8 proceeds according to the pseudo-second-order- model. Under the optimum conditions, the method showed a good linear dynamic range (2–2000 µg L−1), (0.9–4000µg L−1) with a lower limit of detection (0.6 µg L−1), (0.27 µg L−1) and preconcentration factor (62.5), (33.33) for Co (II) and Cd(II) respectively. The relative standard deviations (RSDs) were less than 1.0% for 0.5 mg L−1. The method is highly selective as there are no significant interferences from matrix cations and anions even at high concentrations. These results reveal the potential use of the synthesized ZIF-8 as an effective adsorbent and used for preconcentration of Cd(II) and Co(II) ions from environmental samples.

Rapid control and prevention of diseases caused by foodborne pathogens is one of the existing food safety regulatory issues faced by various countries and has received wide attention from all sectors of society. The development of rapid and reliable detection methods for foodborne pathogens remains a hot research area for food safety and public health because of the limitations of complex steps, time-consuming, low sensitivity, or poor selectivity of commonly used methods. Surface-enhanced Raman spectroscopy (SERS), as a novel spectroscopic technique, has the advantages of high sensitivity, selectivity, rapid and nondestructive detection and has exhibited broad application prospects in the determination of pathogenic bacteria. In this study, the enhancement mechanisms of SERS are briefly introduced, then the characteristics and properties of liquid-phase, rigid solid-phase, and flexible solid-phase are categorized. Furthermore, a comprehensive review of the advances in label-free or label-based SERS strategies and SERS-compatible techniques for the detection of foodborne pathogens is provided, and the advantages and disadvantages of these methods are reviewed. Finally, the current challenges of SERS technology applied in practical applications are listed, and the possible development trends of SERS in the field of foodborne pathogens detection in the future are discussed.

Molecular Subtyping and the Transformation of Public Health