Solid electrochemiluminescence sensor by immobilization luminol in Zn-Co-ZIF CNFs for sensitive detection of procymidone in vegetables.

A solid-state electrochemiluminescence (ECL) sensor was fabricated by immobilizing luminol, a classical luminescent reagent, on a Zn-Co-ZIF carbon fiber-modified electrode for the rapid and sensitive detection of procymidone (PCM) in vegetable samples. The sensor was created by sequentially modifying the glassy carbon electrode with Zn-Co-ZIF carbon fiber (Zn-Co-ZIF CNFs), Pt@Au NPs, and luminol. Zn-Co-ZIF CNFs, prepared through electrospinning and high-temperature pyrolysis, possessed a large specific surface area and porosity, making it suitable as carrier and electron transfer accelerator in the system. Pt@Au NPs demonstrated excellent catalytic activity, effectively enhancing the generation of active substances. The ECL signal was significantly amplified by the combination of Zn-Co-ZIF CNFs and Pt@Au NPs, which can subsequently be diminished by procymidone. The ECL intensity decreased proportionally with the addition of procymidone, displaying a linear relationship within the concentration range 1.0 × 10-13 to 1.0 × 10-6 mol L-1 (R2 = 0.993). The sensor exhibited a detection limit of 3.3 × 10-14 mol L-1 (S/N = 3) and demonstrated outstanding reproducibility and stability, making it well-suited for the detection of procymidone in vegetable samples.

Sensitive detection of uric acid based on low-triggering-potential cathodic luminol electrochemiluminescence achieved by ReS2 nanosheets.

The majority of previously reported cathodic electrochemiluminescence (ECL) systems often required very negative potential to be carried out, which has greatly limited their applications in the sensing field. Screening high-performance cathodic ECL systems with low triggering potential is a promising way to broaden their applications. In this work, rhenium disulfide nanosheets (ReS2 NS) have been revealed as an efficient co-promoter to realize low-triggering-potential cathodic luminol ECL. One strong cathodic ECL signal appeared at a potential of -0.3 V and one anodic ECL peak was obtained at -0.15 V under the reverse potential scan, which were caused by electrogenerated reactive oxygen species (ROS) from hydrogen peroxide. The generation of strong luminol ECL at low potential was the result of the electrocatalytic effect of ReS2 NS on the reduction of H2O2. The scavenging effect of uric acid (UA) on the ROS could significantly inhibit the cathodic ECL. As a result, an ECL sensor was proposed, which showed outstanding performance for the detection of UA in the range of 10 nM to 0.1 mM with a low detection limit of 1.53 nM. Moreover, the ECL sensor was successfully applied in the sensitive detection of UA in real samples. This work provides a new avenue to establish a low-potential cathodic ECL system, which will sufficiently expand the potential application of cathodic ECL in the sensing field.

Enhanced luminol electrochemiluminescence biosensing system based on highly dispersed bimetallic nanozyme coreaction accelerator and 3D DNA walker signal amplifier.

In this work, a platinum-nickel based nanozyme is prepared and used as a coreaction accelerator in the luminol-H2O2 electrochemiluminescence (ECL) system to construct an ECL biosensor for dimethyl phthalate (DMP) detection. The PtNi/NC nanozyme possesses dispersed metal active sites, and the synergistic effect of Pt and Ni endows it with excellent catalytic performance, which effectively converts H2O2 into more superoxide anions, and then significantly enhances the ECL intensity of the luminol system. The ECL mechanism is investigated by combining cyclic voltammetry and ECL with different types of free radical scavengers. Simultaneously, an "off-on" biosensor is constructed by integrating 3D DNA walker with enzyme-free recycling amplification for ultrasensitive detection of DMP. The biosensor based on PtNi/NC nanozyme mediated luminol-H2O2 system and 3D DNA walker exhibits a linear range of 1 × 10-16 to 1 × 10-6 M with a detection limit of 4.3 × 10-17 M (S/N = 3), and displays good stability and specificity. This study demonstrates the advantages of PtNi/NC nanozyme in enhancing the luminol-H2O2 ECL system, providing new strategy for designing efficient ECL emitter and offering a new method for detecting phthalate esters.

A highly sensitive luminescent aptasensor utilizing MOF-74-co encapsulation of luminol in a 'turn-on' mode for streptomycin detection.

This study focused on detecting streptomycin (STR) residues using a luminescent aptasensor encapsulated with aptamer. Utilizing MOF-74-Co with peroxidase-like activity, luminol was enclosed in its pores. The specific STR aptamer acted as a gatekeeper, ensuring excellent performance. Upon exposure to STR, the aptamers detached, releasing luminol and amplifying the luminescent signal through MOF-74-Co catalytic activity. A linear relationship between fluorescence intensity and STR concentration (50 nM âˆ¼ 5 × 106 nM) was established, with a limit of detection of 0.065 nM. The sensor exhibited high selectivity for STR even in the presence of other aminoglycoside antibiotics. Applied to tea, egg, and honey samples, the sensor showed recovery rates of 91.38-100.2%, meeting safety standards. This MOF-based aptasensor shows promise for detecting harmful residues.

In-situ analysis of sub-nanomolar level of Fe(II) in open-ocean waters.

Iron (Fe) in seawater is an essential micronutrient for marine phytoplankton, and Fe deficiency limits their growth in high-nutrient, low-chlorophyll areas. The bioavailability of Fe for phytoplankton largely depends on its chemical speciation in seawater. In surface water, the reduction of Fe(III) to Fe(II) is an important step in the uptake of Fe by phytoplankton. However, the marine biogeochemical cycle of Fe(II) in the open ocean has not been fully investigated. In oxic open-ocean waters, Fe(II) is rapidly oxidized and exists at sub-nanomolar levels, making it difficult to determine the Fe(II) concentration of seawater. In this study, we applied the flow analytical method of determining the Fe(II) concentration of seawater using luminol chemiluminescence in an in-situ analyzer (geochemical anomaly monitoring system, GAMOS). In the onboard laboratory, we successfully detected sub-nanomolar levels of Fe(II) in seawater using the GAMOS. In the central Indian Ocean, this analyzer was deployed at a depth of 1000 m to determine the Fe(II) concentration in the water column. During deployment, the detection limit (0.48 nM) was insufficient to determine the concentration. Therefore, we need to lower the blank values and enhance the stability of signal of the in-situ analytical method for application to open-ocean seawater samples.

Pre-Adsorbed H-Mediated Electrochemiluminescence.

In conventional electrochemiluminescence (ECL) systems, the presence of the competitive cathodic hydrogen evolution reaction (HER) in aqueous electrolytes is typically considered to be a side reaction, leading to a reduced ECL efficiency and stability due to H2 generation and aggregation at the electrode surface. However, the significant role of adsorbed hydrogen (H*) as a key intermediate, formed during the Volmer reaction in the HER process, has been largely overlooked. In this study, employing the luminol-H2O2 system as a model, we for the first time demonstrate a novel H*-mediated coreactant activation mechanism, which remarkably enhances the ECL intensity. H* facilitates cleavage of the O-O bond in H2O2, selectively generating highly reactive hydroxyl radicals for efficient ECL reactions. Experimental investigations and theoretical calculations demonstrate that this H*-mediated mechanism achieves superior coreactant activation compared to the conventional direct electron transfer pathway, which unveils a new pathway for coreactant activation in the ECL systems.

Electrogenerated chemiluminescence from luminol-labelled microbeads triggered by in situ generation of hydrogen peroxide.

We developed a sensing strategy that mimics the bead-based electrogenerated chemiluminescence immunoassay. However, instead of the most common metal complexes, such as Ru or Ir, the luminophore is luminol. The electrogenerated chemiluminescence of luminol was promoted by in situ electrochemical generation of hydrogen peroxide at a boron-doped diamond electrode. The electrochemical production of hydrogen peroxide was achieved in a carbonate solution by an oxidation reaction, while at the same time, microbeads labelled with luminol were deposited on the electrode surface. For the first time, we proved that was possible to obtain light emission from luminol without its direct oxidation at the electrode. This new emission mechanism is obtained at higher potentials than the usual luminol electrogenerated chemiluminescence at 0.3-0.5 V, in conjunction with hydrogen peroxide production on boron-doped diamond at around 2-2.5 V (vs Ag/AgCl).

Preliminary study on mitochondrial DNA analysis from different sports items.

Criminals often attempt to conceal blood-stained weapons used in violent crimes, making forensic evidence crucial in solving cases. This study explores the recovery and extraction of trace DNA from sports equipment, including cricket bats, table tennis racquets, and hockey sticks, which are frequently implicated in such incidents. Our research evaluates various double swab collection methods for retrieving trace DNA from these sports items, emphasizing those associated with blunt force trauma. We also compare presumptive and confirmatory tests to establish a direct correlation. This research consistently demonstrated robust DNA recovery, surpassing a 50 % threshold across all tests. Specifically, DNA recovery from buried samples reached an impressive 87 %, while washed samples still yielded a substantial 80 % efficiency. We conducted a comparative analysis between presumptive and confirmatory testing methods, establishing a direct correlation between the two. Variability in DNA recovery efficiency was observed and attributed to factors like the type of surface the items contacted, and ambient humidity levels. In addition to presenting robust DNA recovery rates, statistical analyses were employed to compare methods, establishing correlations and highlighting the influence of environmental factors on DNA recovery efficiency. These findings have significant implications for forensic investigations involving silent weapons crafted from sports equipment, emphasizing the need for standardized protocols and consideration of environmental factors in DNA analysis.

Electrochemiluminescence resonance energy transfer detection of HBsAg based on Co doped 3D porous luminol-based conjugates and quencher UiO-66-NH2@Au.

An electrochemiluminescence (ECL) biosensor based on ECL resonance energy transfer (ECL-RET) was designed to sensitively detect hepatitis B virus surface antigen (HBsAg). In this ECL-RET system, luminol was employed as ECL donor, and gold nanoparticles functionalized zirconium organoskeleton (UiO-66-NH2@Au) was prepared and served as ECL acceptor. The UiO-66-NH2@Au possessed an ultraviolet-visible (UV-vis) absorption between 400 nm and 500 nm, and the absorption spectra overlapped with the ECL spectrum of luminol. Furthermore, Graphene oxide-poly(aniline-luminol)-cobalt nanoparticles conjugates (GO-PALu-Co) was prepared to optimize the ECL behavior through the catalysis of Cobalt nanoparticles and served as a stable 3D porous film to load capture probe primary antibody (Ab1). Based on the ECL-RET biosensing method, the UiO-66-NH2@Au-labeled Ab2 and target HBsAg could pair with primary antibody Ab1 to form sandwich-type structure, and the ECL signal of GO-PALu-Co was quenched. Under optimized experimental conditions, the ECL-RET analytical method represented eminent analytical performance for HBsAg detection with a wide linear relationship from 2.2 × 10-13 to 2.2 × 10-5 mg/mL, and a detection limit of 9 × 10-14 mg/mL (S/N = 3), with spiked sample recoveries ranging from 97.27 % to 102.73 %. The constructed sensor has good stability, reproducibility, and specificity. It can be used to detect HBsAg in human serum and has the potential to be used for the sensitive detection of other disease biomarkers.

CRET-based immunoassay on magnetic beads for selective and sensitive detection of Nanog antigen as a key cancer stem cell marker.

A method is presented for chemiluminescence resonance energy transfer (CRET) using APTES-Fe3O4 as a highly efficient energy acceptor with strong magnetic effectiveness over extended distances, while an Au@BSA-luminol composite acts as the donor. In order to boost the chemiluminescence reactions, CuO nanoparticles were successfully employed. The distance between the donor and acceptor is a crucial factor in the occurrence of the CRET phenomenon. A sensitive and high-throughput sandwich chemiluminescence immunosensor has been developed accordingly with a linear range of 1.0 × 10-7 g/L to 6.0 × 10-5 g/L and a limit of detection of 0.8 × 10-7 g/L. The CRET-based sandwich immunosensor has the potential to be implemented to early cancer diagnosis because of its high sensitivity in detecting Nanog, fast analysis (30 min), and simplicity. Furthermore, this approach has the potential to be adapted for the recognition of other antigen-antibody immune complexes by utilizing the corresponding antigens and their selective antibodies.

Study on the methods of visualizing bloodstains after thermal exposure.

To establish the correlation between thermal conditions imposed on bloodstains and visualizing effect of enhancement techniques, infrared photography and four chemical enhancement reagents were used to visualize bloodstains following thermal exposure. A black tile was selected as the substrate to intensify the visualization challenge, with a Cone Calorimeter serving as the standardized heating source to control thermal conditions. Compared with standard photography, infrared photography is proven to be a valuable complement to chemical reagents, showing significant advantages in visualizing bloodstains after thermal exposure. However, it is worth noting that infrared image fell short of standard image when bloodstains displayed raised, embossed morphology or when bloodstains almost disappeared under specific conditions. The enhancement effectiveness was found to be strongly correlated with thermal conditions imposed on bloodstains, and the morphology evolution of bloodstains during heating affected the chemical enhancement effect additionally, especially when the bulge morphology was formed, and it was observed that reagents were more effective after removing the dense shell of the bulge. Among the four selected chemical enhancement reagents, fluorescein performed exceptionally well, maintaining its effectiveness even for bloodstains heated at 641°C for 10 min. TMB demonstrated its visualizing ability for bloodstains heated at 396°C for 5 min and heated at 310°C for 20 min. BLUESTAR® followed afterwards, while luminol performed worst. The correlation between thermal conditions imposed on bloodstains and the corresponding visualizing effectiveness of enhancement techniques provides important references for detecting bloodstains at fire scenes.

Quantitative analysis of CL-20 explosive by smartphone-based chemiluminescence method.

A new smartphone-based chemiluminescence method has been introduced for the quantitative analysis of CL-20 (Hexanitroazaisowuertzitan) explosive. The solvent mixture, oxidizer agent, and concentration of the reactants were optimized using statistical procedures. CL-20 explosive showed a quenching effect on the chemiluminescence intensity of the luminol-NaClO reaction in the solvent mixture of DMSO/H2O. A smartphone was used as a detector to record the light intensity of chemiluminescence reaction as a video file. The recorded video file was converted to an analytical signal as intensity luminescence-time curve by a written code in MATLAB software. Dynamic range and limit of detection of the proposed method were obtained 2.0-240.0 and 1.1 mg⋅L-1, respectively, in optimized concentrations 1.5 × 10-3 mol⋅L-1 luminol and 1.0 × 10-2 mol⋅L-1 NaClO. Precursors TADB, HBIW, and TADNIW in CL-20 explosive synthesis did not show interference in measurement the CL-20 purity. The analysis of CL-20 spiked samples of soil and water indicated the satisfactory ability of the method in the analysis of real samples. The interaction of CL-20 molecules and OCl- ions is due to quench of chemiluminescence reaction of the luminol-NaClO.

Evaluation of Forensic Luminol in Detection of Blood Stains in Instruments Following Dental Treatment.

Background Saliva and blood, being biological materials with a high potential for infectious transmission in dental environments, pose significant risks to dental professionals, assistants, and patients alike. Therefore, practitioners must adopt stringent security measures to ensure patient care, considering all parties as potential carriers of microorganisms capable of causing infectious diseases. Currently, various methods of disinfection and sterilization are employed to maintain the aseptic chain effectively. Having reliable methods for detecting substances in liquids, particularly body fluids, is crucial and highly convenient. Luminol, a chemiluminescent agent widely used in forensic science for detecting minute traces of blood that are invisible to the naked eye, presents itself as a valuable tool. Blood, a major bodily fluid often present in instruments following dental procedures, underscores the importance of its detection. Hence, in this study, luminol was utilized to detect blood traces in dental instruments following dental treatment, both before and after sterilization or disinfection. Objective Blood and saliva splashes, together with highly contagious aerosols, are always a part of dental procedures. The objective of the current study is to detect traces of blood stains on face shields, surgical instruments, and endodontic files using luminol before and after sterilization. Materials and methods Sample size calculation was done with G*Power software (Version 3.1.9.4, Düsseldorf, Germany), and a total of 30 instruments were selected for the study. In the present study, a total of 30 items were collected and utilized, including 14 instruments used after implant placement, 12 endodontic files employed after root canal treatment, and four face shields utilized during these procedures. Meanwhile, a freshly prepared luminol solution was applied to these instruments, and they were viewed in a dark environment both before and after sterilization procedures. Luminescence generated by luminol was observed in the instruments, indicative of the presence of blood not visible to the naked eye. Statistical analysis for both groups was done with IBM SPSS Statistics for Windows, Version 16.0 (Released 2007; SPSS Inc., Chicago, IL, USA). Intragroup comparison was done using the Friedman test, and intergroup comparison was done using the Wilcoxon signed-rank test. Results Blood stains and chemiluminescence were visualized in two out of 10 endodontic files (one #15 K-file and #20 K-files) and two out of four face shields. The intragroup comparison was done using the Friedman test, and it was found to be statistically significant (p < 0.05). Intergroup comparison was done using the Wilcoxon signed-rank test and was found to be statistically insignificant (p > 0.05). Conclusion Following sterilization and disinfection, there were no visual blood stains or chemiluminescence. Therefore, luminol was found to be effective in detecting blood stains in endodontic files, surgical instruments, and face shields, as well as in validating the sterilization and disinfection processes. Hence, sterilization in dentistry stands as a critical measure to guarantee patient safety, halt the dissemination of infections, and uphold exemplary clinical care standards.

In vitro assessment of thyroid peroxidase inhibition by chemical exposure: comparison of cell models and detection methods.

Disruption of the thyroid hormone (TH) system is connected with diverse adverse health outcomes in wildlife and humans. It is crucial to develop and validate suitable in vitro assays capable of measuring the disruption of the thyroid hormone (TH) system. These assays are also essential to comply with the 3R principles, aiming to replace the ex vivo tests often utilised in the chemical assessment. We compared the two commonly used assays applicable for high throughput screening [Luminol and Amplex UltraRed (AUR)] for the assessment of inhibition of thyroid peroxidase (TPO, a crucial enzyme in TH synthesis) using several cell lines and 21 compounds from different use categories. As the investigated cell lines derived from human and rat thyroid showed low or undetectable TPO expression, we developed a series of novel cell lines overexpressing human TPO protein. The HEK-TPOA7 model was prioritised for further research based on the high and stable TPO gene and protein expression. Notably, the Luminol assay detected significant peroxidase activity and signal inhibition even in Nthy-ori 3-1 and HEK293T cell lines without TPO expression, revealing its lack of specificity. Conversely, the AUR assay was specific to TPO activity. Nevertheless, despite the different specificity, both assays identified similar peroxidation inhibitors. Over half of the tested chemicals with diverse structures and from different use groups caused TPO inhibition, including some widespread environmental contaminants suggesting a potential impact of environmental chemicals on TH synthesis. Furthermore, in silico SeqAPASS analysis confirmed the high similarity of human TPO across mammals and other vertebrate classes, suggesting the applicability of HEK-TPOA7 model findings to other vertebrates.

Efficient chemiluminescence of luminol in the presence of hemin without added hydrogen peroxide†.

The results reported herein demonstrate for the first time that typical reducing agents in an alkaline medium initiate chemiluminescence of luminol in the presence of hemin, and the efficiency of their action is comparable to that of hydrogen peroxide and exceeds it in the case of the superoxide anion. The pertinent implications of these findings refer to new possibilities for developing chemiluminescence assays and biosensors and to precautions for determining hydrogen peroxide using luminol and hemin in samples of unknown composition, most prominently, of biological origin.

Coreactant-free aggregation-induced electrochemiluminescence system based on the novel zinc-luminol metal-organic gel for ultrasensitive detection of PiRNA-823.

Aggregation-induced electrochemiluminescence (AIECL) technology has aroused widespread interest due to the significant improve in ECL response by solving the problems of aggregation-caused quenching and poor water solubility of the luminophore. However, the existing AIECL emitters still suffer from low ECL efficiency, additional coreactants and complex synthesis steps, which greatly limit their applications. Herein, luminol, as a kind of AIE molecule, was assembled with Zn2+ nodes to obtain a novel microflower-like Zinc-luminol metal-organic gel (Zn-MOG) by one-step method. In the light of the strong affinity of N atoms in luminol ligand to Zn2+, Zn-MOG with vigorous viscosity and stability can be formed immediately after vortex oscillation, overcoming the main difficulties of the complicated synthesis steps and poor film-forming performance encountered in current AIECL materials. Impressively, an AIECL resonance energy transfer (RET) biosensor was constructed using Zn-MOG as a donor and Alexa Fluor 430 as an acceptor in combination with DNA-Fuel-driven target recycling amplification for the ultrasensitive detection of PiRNA-823. The fabricated biosensor exhibited a wide linear relationship in the range of 100 aM to 100 pM and a detection limit as low as 60.0 aM. This work is the first to realize the construction of ECL emitters using the AIE effect of luminol, which provides inspiration for the design of AIECL systems without adding coreactants.

FeNi-MIL-88B-based electrochemiluminescence immunosensor for ultra-sensitive detection of CD44 protein via dual-quenching strategy.

BACKGROUND: Cluster of Differentiation 44 (CD44) is considered an important biomarker for various cancers, and achieving highly sensitive detection of CD44 is crucial, which plays a significant role in tumor invasion and metastasis, providing essential information for clinical tumor diagnosis. Commonly used methods for analysis include fluorescence spectroscopy (FL), photoelectrochemical analysis (PEC), electrochemical analysis (EC), and commercial ELISA kits. Although these methods offer high sensitivity, they can be relatively complex to perform experimentally. Electrochemiluminescence (ECL) has gained widespread research attention due to its high sensitivity, ease of operation, effective spatiotemporal control, and close to zero background signal. RESULTS: In this work, a sandwich-type ECL immunosensor for detecting CD44 was constructed using luminol as a luminophore. In this sensing platform, bimetallic MOFs (Pd@FeNi-MIL-88B) loaded with palladium nanoparticles (Pd NPs) were used as a novel enzyme mimic, exhibiting excellent catalytic performance towards the electroreduction of H2O2. The hybrids provided a strong support platform for luminol and antibodies, significantly enhancing the initial ECL signal of luminol. Subsequently, core-shell Au@MnO2 nanocomposites were synthesised by gold nanoparticles (Au NPs) encapsulated in manganese dioxide (MnO2) thin layers, as labels. In the luminol/H2O2 system, Au@MnO2 exhibited strong light absorption in the broad UV-vis spectrum, similar to the black body effect, and the scavenging effect of Mn2+ on O2•-, which achieved the dual-quenching of ECL signal. Under the optimal experimental conditions, the immunosensor demonstrated a detection range of 0.1 pg mL-1 - 100 ng mL-1, with a detection limit of 0.069 pg mL-1. SIGNIFICANCE: Based on Pd@FeNi-MIL-88B nanoenzymes and Au@MnO2 nanocomposites, a dual-quenching sandwich-type ECL immunosensor for the detection of CD44 was constructed. The proposed immunosensor exhibited excellent reproducibility, stability, selectivity, and sensitivity, and provided a valuable analytical strategy and technical platform for the accurate detection of disease biomarkers, and opened up potential application prospects for early clinical treatment.

Tuning electrochemical water activation over NiIr single-atom alloy aerogels for stable electrochemiluminescence.

The anodic oxygen evolution reaction is a well-acknowledged side reaction in traditional aqueous electrochemiluminescence (ECL) systems due to the generation and surface aggregation of oxygen at the electrode, which detrimentally impacts the stability and efficiency of ECL emission. However, the effect of reactive oxygen species generated during water oxidation on ECL luminophores has been largely overlooked. Taking the typical luminol emitter as an example, herein, we employed NiIr single-atom alloy aerogels possessing efficient water oxidation activity as a prototype co-reaction accelerator to elucidate the relationship between ECL behavior and water oxidation reaction kinetics for the first time. By regulating the concentration of hydroxide ions in the electrolyte, the electrochemical oxidation processes of both luminol and water are finely tuned. When the concentration of hydroxide ions in electrolyte is low, the kinetics of water oxidation is attenuated, which limits the generation of oxygen, effectively mitigates the influence of oxygen accumulation on the ECL strength, and offers a novel perspective for harnessing side reactions in ECL systems. Finally, a sensitive and stable sensor for antioxidant detection was constructed and applied to the practical sample detection.

Luminol-conjugated cyclodextrin biological nanoparticles for the treatment of severe burn-induced intestinal barrier disruption.

Background: The breakdown of intestinal barrier integrity occurs after severe burn injury and is responsible for the subsequent reactions of inflammation and oxidative stress. A new protective strategy for the intestinal barrier is urgently needed due to the limitations of the traditional methods. Recently, the application of nanoparticles has become one of the promising therapies for many inflammation-related diseases or oxidative damage. Herein, we developed a new anti-inflammatory and antioxidant nanoparticle named luminol-conjugated cyclodextrin (LCD) and aimed to evaluate its protective effects in severe burn-induced intestinal injury. Methods: First, LCD nanoparticles, engineered with covalent conjugation between luminol and ß-cyclodextrin (ß-CD), were synthesized and examined. Then a mouse burn model was successfully established before the mouse body weight, intestinal histopathological manifestation, permeability, tight junction (TJ) expression and pro-inflammatory cytokines were determined in different groups. The proliferation, apoptosis, migration and reactive oxygen species (ROS) of intestinal epithelial cells (IECs) were assessed. Intraepithelial lymphocytes (IELs) were isolated and cultured for analysis by flow cytometry. Results: LCD nanoparticle treatment significantly relieved the symptoms of burn-induced intestinal injury in the mouse model, including body weight loss and intestinal permeability abnormalities. Moreover, LCD nanoparticles remarkably recovered the mechanical barrier of the intestine after severe burn, renewed TJ structures, promoted IEC proliferation and migration, and inhibited IEC apoptosis. Mechanistically, LCD nanoparticles dramatically alleviated pro-inflammation factors (tumor necrosis factor-α, IL-17A) and ROS accumulation, which could be highly involved in intestinal barrier disruption. Furthermore, an increase in IL-17A and the proportion of IL-17A+Vγ4+ γδ T subtype cells was also observed in vitro in LPS-treated Vγ4+ γδ T cells, but the use of LCD nanoparticles suppressed this increase. Conclusions: Taken together, these findings demonstrate that LCD nanoparticles have the protective ability to ameliorate intestinal barrier disruption and provide a therapeutic intervention for burn-induced intestinal injury.

Evaluation of the effect of ozone disinfection on forensic identification of blood, saliva, and semen stains.

Good laboratory practice minimizes the biological hazard posed by potentially infectious casework samples. In certain scenarios, when the casework sample is contaminated with highly contagious pathogens, additional safety procedures such as disinfection might be advised. It was previously proven that ozone gas treatment does not hamper STR analysis, but there is no data on how the disinfection affects other steps of the forensic analysis. In this study, we aimed to assess the interference of ozone disinfection with forensic tests used to identify biological stains. A dilution series of blood, saliva, and semen samples were pipetted onto cotton fabric and let completely dry. Half of the samples were subjected to ozone treatment, while the rest served as controls. All the samples were tested with specific lateral flow immunochromatographic assays and for specific RNA markers with quantitative real-time PCR. Additionally, luminol test was carried out on blood spots, Phadebas® Amylase Test on saliva stains, and semen stains were examined with STK Lab kit and light microscope following Christmas Tree or Hematoxylin-Eosin staining. Ozone treatment had no detrimental effect on the microscopic identification of sperm cells. Undiluted blood samples were detected with luminol and immunoassay, but at higher dilution, the sensitivity of the test decreased after disinfection. The same decrease in sensitivity was observed in the detection of semen stains using STK Lab kit from STK® Sperm Tracker, and in the case of the immunoassay specific for prostate-specific antigen (PSA). Ozone treatment almost completely inhibited the enzymatic activity of amylase. The sensitivity of antibody-based detection of amylase was also greatly reduced. RNA markers showed degradation but remained detectable in blood and semen samples after incubation in the presence of ozone. In saliva, the higher Ct values of the mRNA markers were close to the detection limit, even before ozone treatment.