The colorful world of carotenoids: a profound insight on therapeutics and recent trends in nano delivery systems.

The therapeutic effects of carotenoids as dietary supplements to control or even treat some specific diseases including diabetic retinopathy, cardiovascular diseases, bacterial infections, as well as breast, prostate, and skin cancer are discussed in this review and also thoughts on future research for their widespread use are emphasized. From the stability standpoint, carotenoids have low bioavailability and bioaccessibility owing to their poor water solubility, deterioration in the presence of environmental stresses such as oxygen, light, and high heat as well as rapid degradation during digestion. Nanoencapsulation technologies as wall or encapsulation materials have been increasingly used for improving food product functionality. Nanoencapsulation is a versatile process employed for the protection, entrapment, and the delivery of food bioactive products including carotenoids from diverse environmental conditions for extended shelf lives and for providing controlled release. Therefore, we present here, recent (mostly during the last five years) nanoencapsulation methods of carotenoids with various nanocarriers. To us, this review can be considered as the first highlighting not only the potential therapeutic effects of carotenoids on various diseases but also their most effective nanodelivery systems.HighlightsBioactive compounds are of deep interest to improve food properties.Carotenoids (such as ß-carotene and xanthophylls) play indispensable roles in maintaining human health and well-being.A substantial research effort has been carried out on developing beneficial nanodelivery systems for various carotenoids.Nanoencapsulation of carotenoids can enhance their functional properties.Stable nanoencapsulated carotenoids could be utilized in food products.

Improved green biosynthesis of chitosan decorated Ag- and Co3O4-nanoparticles: A relationship between surface morphology, photocatalytic and biomedical applications.

AgNPs@Chitosan and Co3O4-NPs@Chitosan were fabricated with Salvia hispanica. Results showed MZI values of 5 and 30 mm for Co3O4-NPs- and AgNPs@Chitosan against S. aureus, and 15 and 21 mm for Co3O4-NPs- and AgNPs@Chitosan against E. coli (24 h, 20 µg/mL), respectively. MTT assays showed up to 80% and 90%, 71% and 75%, and 91% and 94% mammalian cell viability for the green synthesized, chemically synthesized AgNPs and green synthesized AgNPs@Chitosan for HEK-293 and PC12 cells, respectively, and 70% and 71%, 59% and 62%, and 88% and 73% for the related Co3O4-NPs (24 h, 20 µg/mL). The photocatalytic activities showed dye degradation after 135 and 105 min for AgNPs@Chitosan and Co3O4-NPs@Chitosan, respectively. FESEM results showed differences in particle sizes (32 ±â€¯3.0 nm for the AgNPs and 41 ±â€¯3.0 nm for the Co3O4NPs) but AFM results showed lower roughness of the AgNPs@Chitosan (7.639 ±â€¯0.85 nm) compared to Co3O4NPs@Chitosan (9.218 ±â€¯0.93 nm), which resulted in potential biomedical applications.

Green synthesis of CuO- and Cu2O-NPs in assistance with high-gravity: The flowering of nanobiotechnology.

This study, for the first time, reports the synthesis of CuO- and Cu2O nanoparticles (NPs) using the Salvia hispanica extract by a high-gravity technique. The original green synthesis procedure led to the formation of nanoparticles with promising catalytic and biological properties. The synthesized nanoparticles were fully characterized and their catalytic activity was evaluated through a typical Azide-Alkyne Cycloaddition (AAC) reaction. The potential antibacterial activity against gram positive (S. aureus) and gram negative (E. coli) bacteria were investigated. It was shown that the antibacterial properties were independent of the NP morphology as well as of the texture of the synthesis media. As a result, the presently synthesized nanoparticles showed very good photocatalytic and catalytic activities in comparison with the literature. From a biological perspective, they showed lower cytotoxicity in comparison with the literature, and also showed higher antioxidant and antibacterial activities. Thus, these present green CuO and Cu2O nanoparticles deserve further attention to improve numerous medical applications.

Epidemiology of facial fractures: incidence, prevalence and years lived with disability estimates from the Global Burden of Disease 2017 study.

BACKGROUND: The Global Burden of Disease Study (GBD) has historically produced estimates of causes of injury such as falls but not the resulting types of injuries that occur. The objective of this study was to estimate the global incidence, prevalence and years lived with disability (YLDs) due to facial fractures and to estimate the leading injurious causes of facial fracture. METHODS: We obtained results from GBD 2017. First, the study estimated the incidence from each injury cause (eg, falls), and then the proportion of each cause that would result in facial fracture being the most disabling injury. Incidence, prevalence and YLDs of facial fractures are then calculated across causes. RESULTS: Globally, in 2017, there were 7 538 663 (95% uncertainty interval 6 116 489 to 9 493 113) new cases, 1 819 732 (1 609 419 to 2 091 618) prevalent cases, and 117 402 (73 266 to 169 689) YLDs due to facial fractures. In terms of age-standardised incidence, prevalence and YLDs, the global rates were 98 (80 to 123) per 100 000, 23 (20 to 27) per 100 000, and 2 (1 to 2) per 100 000, respectively. Facial fractures were most concentrated in Central Europe. Falls were the predominant cause in most regions. CONCLUSIONS: Facial fractures are predominantly caused by falls and occur worldwide. Healthcare systems and public health agencies should investigate methods of all injury prevention. It is important for healthcare systems in every part of the world to ensure access to treatment resources.

Epidemiology of injuries from fire, heat and hot substances: global, regional and national morbidity and mortality estimates from the Global Burden of Disease 2017 study.

BACKGROUND: Past research has shown how fires, heat and hot substances are important causes of health loss globally. Detailed estimates of the morbidity and mortality from these injuries could help drive preventative measures and improved access to care. METHODS: We used the Global Burden of Disease 2017 framework to produce three main results. First, we produced results on incidence, prevalence, years lived with disability, deaths, years of life lost and disability-adjusted life years from 1990 to 2017 for 195 countries and territories. Second, we analysed these results to measure mortality-to-incidence ratios by location. Third, we reported the measures above in terms of the cause of fire, heat and hot substances and the types of bodily injuries that result. RESULTS: Globally, there were 8 991 468 (7 481 218 to 10 740 897) new fire, heat and hot substance injuries in 2017 with 120 632 (101 630 to 129 383) deaths. At the global level, the age-standardised mortality caused by fire, heat and hot substances significantly declined from 1990 to 2017, but regionally there was variability in age-standardised incidence with some regions experiencing an increase (eg, Southern Latin America) and others experiencing a significant decrease (eg, High-income North America). CONCLUSIONS: The incidence and mortality of injuries that result from fire, heat and hot substances affect every region of the world but are most concentrated in middle and lower income areas. More resources should be invested in measuring these injuries as well as in improving infrastructure, advancing safety measures and ensuring access to care.

High-gravity-assisted green synthesis of palladium nanoparticles: the flowering of nanomedicine.

This study investigated the synthesis of Pd nanoparticles (NPs) using a high-gravity technique mediated by Salvia hispanica leaf extracts. Biological assays confirmed their antibacterial activity against gram positive (S. aureus) and gram negative (E. coli) bacteria with significant antioxidant activity in comparison with the standards as well as low cellular toxicity on PC12 and HEK293 cell lines. To the best of our knowledge, this study can be considered as the first investigation of Pd-NPs synthesized by Salvia hispanica leaf extracts assisted by a high-gravity technique. In addition, the mentioned green synthesis procedure led to the formation of nanoparticles with considerable antibacterial properties independent of the morphology and texture of the green media of these nanoparticles. Considering the increasing rate of antimicrobial resistant bacteria deaths worldwide, this study introduces a novel green synthesis method and non-antibiotic nanoparticle which should be studied for a wide range of medical applications.

Point-of-Use Rapid Detection of SARS-CoV-2: Nanotechnology-Enabled Solutions for the COVID-19 Pandemic.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) caused the COVID-19 pandemic that has been spreading around the world since December 2019. More than 10 million affected cases and more than half a million deaths have been reported so far, while no vaccine is yet available as a treatment. Considering the global healthcare urgency, several techniques, including whole genome sequencing and computed tomography imaging have been employed for diagnosing infected people. Considerable efforts are also directed at detecting and preventing different modes of community transmission. Among them is the rapid detection of virus presence on different surfaces with which people may come in contact. Detection based on non-contact optical techniques is very helpful in managing the spread of the virus, and to aid in the disinfection of surfaces. Nanomaterial-based methods are proven suitable for rapid detection. Given the immense need for science led innovative solutions, this manuscript critically reviews recent literature to specifically illustrate nano-engineered effective and rapid solutions. In addition, all the different techniques are critically analyzed, compared, and contrasted to identify the most promising methods. Moreover, promising research ideas for high accuracy of detection in trace concentrations, via color change and light-sensitive nanostructures, to assist fingerprint techniques (to identify the virus at the contact surface of the gas and solid phase) are also presented.

Magnetically Recoverable TiO2/SiO2/γ-Fe2O3/rGO Composite with Significantly Enhanced UV-Visible Light Photocatalytic Activity.

In this paper, we report the preparation of a new composite (TiO2/SiO2/γ-Fe2O3/rGO) with a high photocatalytic efficiency. The properties of the composite were examined by different analyses, including X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), UV-Visible light diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, vibrating-sample magnetometer (VSM), and nitrogen gas physisorption (BET) studies. The photocatalytic efficiency of the proposed composite was evaluated by the degradation of methylene blue under UV and visible light, and the results were compared with titanium dioxide (TiO2), where degradation increased from 30% to 84% and 4% to 66% under UV and visible light, respectively. The significant increase in photocatalytic activity may be explained by the higher adsorption of dye on the surface of the composite and the higher separation and transfer of charge carriers, which in turn promote active sites and photocatalytic efficiency.

Microfluidic devices with gold thin film channels for chemical and biomedical applications: a review.

Microfluidic systems (MFS) provide a range of advantages in biomedical applications, including improved controllability of material characteristics and lower consumption of reagents, energy, time and money. Fabrication of MFS employs various materials, such as glass, silicon, ceramics, paper, and metals such as gold, copper, aluminum, chromium and titanium. In this review, gold thin film microfluidic channels (GTFMFC) are discussed with reference to fabrication methods and their diverse use in chemical and biomedical applications. The advantages of gold thin films (GTF) include flexibility, ease of manufacture, adhesion to polymer surfaces, chemical stability, good electrical conductivity, surface plasmon resonance effects, ability to be chemically functionalized, etc. Various electroactuators and electroanalytical devices can incorporate GTF. GTF-based MFS have been used in environmental monitoring, assays of biomarkers, immunoassays, cell culture studies and pathogen identification.

Rapid and efficient removal of methylene blue dye from aqueous solutions using extract-modified Zn-Al LDH.

Environmental pollution, particularly water pollution caused by organic substances like synthetic dyes, is a pressing global concern. This study focuses on enhancing the adsorption capacity of layered double hydroxides (LDHs) to remove methylene blue (MB) dye from water. The synthesized materials are characterized using techniques like FT-IR, XRD, SEM, TEM, TGA, EDS, BET, BJH, AFM, and UV-Vis DRS. Adsorption experiments show that Zn-Al LDH@ext exhibits a significant adsorption capacity for MB dye compared to pristine LDH. In addition, Zn-Al LDH@ext shows a significant increase in stability, which is attributed to the presence of phenolic compounds in the extract and the interactions between the functional groups of the extract and LDH. The pH and adsorbent dosage optimizations show that pH 7 and 0.7 g of Zn-Al LDH@ext are optimal conditions for efficient MB removal. The study assessed adsorption kinetics through the examination of Langmuir, Freundlich, and Temkin isotherms. Additionally, four kinetic models, namely pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich, were analyzed. The results indicated that the Temkin isotherm (R2 = 0.9927), and pseudo-second-order (R2 = 0.9999) kinetic provided the best fit to the experimental data. This study introduces a novel approach to enhance adsorption efficiency using modified LDHs, contributing to environmentally friendly and cost-effective water treatment methods.

Visible Light-Driven Photocatalytic Degradation of Methylene Blue Dye Using a Highly Efficient Mg-Al LDH@g-C3N4@Ag3PO4 Nanocomposite.

The issue of water resource pollution resulting from the discharge of dyes is a matter of great concern for the environment. In this investigation, a new ternary heterogeneous Mg-Al LDH@g-C3N4X@Ag3PO4Y (X = wt % of g-C3N4 with respect to Mg-Al layered double hydroxide (LDH) and Y = wt % of Ag3PO4 loaded on Mg-Al LDH@g-C3N430) nanocomposite was prepared with the aim of increasing charge carrier separation and enhancement of photocatalytic performance to degrade methylene blue (MB) dye. The prepared samples were subjected to characterization via Fourier-transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy, X-ray diffraction, UV-vis diffuse reflectance spectroscopy, photoluminescence, and photoelectrochemical analysis. It was observed that in the presence of the composite of Mg-Al LDH and g-C3N4, the photocatalytic decomposition of MB under 150 W mercury lamp illumination increases significantly as opposed to Mg-Al LDH alone, and the Mg-Al LDH@g-C3N4 level with Ag3PO4 coating causes the complete degradation of MB to occur in less time. The outcomes show that the Mg-Al LDH@g-C3N430@Ag3PO45 nanocomposite demonstrated the highest photodegradation activity (99%). Scavenger tests showed that the two most effective agents in the photodegradation of MB are holes and hydroxyl radicals, respectively. Finally, a type II heterojunction photocatalytic degradation mechanism for MB by Mg-Al LDH@g-C3N430@Ag3PO45 was proposed.

Comparative study of synthesis methods and pH-dependent adsorption of methylene blue dye on UiO-66 and NH2-UiO-66.

Metal-organic frameworks (MOFs) are highly promising adsorbents with notable properties such as elevated adsorption capacities and versatile surface design capabilities. This study introduces two distinct synthesis methods, one lasting 1 h and the other 24 h, for UiO-66 and NH2-UiO-66. While both methods yield structures with comparable crystallinity and morphology, the adsorption performance of the cationic methylene blue dye varies at different pH levels. Despite the 24 h synthesis time being optimal for maximum adsorption in both MOFs, the relative difference in NH2-UiO-66 adsorption percentage at different times suggests reduced dependency on synthesis time for this property. Notably, NH2-UiO-66 exhibits consistent and effective performance across three pH levels, warranting further investigation into its adsorption kinetics and isotherm. The achievement of high adsorption efficiency coupled with a significantly reduced synthesis time underscores the importance of developing simplified synthetic methods, essential for enhancing the practical applicability of MOFs in diverse applications.

Bioengineered Smart Nanocarriers for Breast Cancer Treatment: Adorned Carbon-Based Nanocomposites with Silver and Palladium Complexes for Efficient Drug Delivery.

Biocompatible and bioactive carbon-based nanocomposites are ingeniously designed and fabricated with the aim of enhancing drug delivery applicability in breast cancer treatment. Reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) are utilized as nanocarriers for increasing penetrability into cells and the loading capacity. What sets our study apart is the strategic incorporation of the two different complexes of silver (AgL2) and palladium (PdL2) with the carboxamide-based ligand C9H7N3OS (L), which have been synthesized and decorated on nanocarriers alongside doxorubicin (DOX) for stabilizing DOX by π-π interactions and hydrogen bonding. Although DOX is a well-known cancer therapy agent, the efficacy of DOX is hindered owing to drug resistance, poor internalization, and limited site specificity. Aside from stabilizing DOX on nanocarriers, our carbon-based nanocarriers are tailored to act as a precision-guided missile, strategically by adorning with target-sensitive complexes. Based on the literature, carboxamide ligands can connect to overexpressed receptors on cancerous cells and inhibit them from proliferation signaling. Also, the complexes have an antibacterial activity that can control the infection caused by decreasing white blood cells and necrosis of cancerous cells. A high-concentration cytotoxicity assay revealed that decorating PdL2 on a DOX-containing nanocarrier not only increased cytotoxicity to breast cancerous cell lines (MDA-MB-231 and MCF-7) but also revealed higher cell viability on a normal cell line (MCF-10A). The drug release screening results showed that the presence of PdL2 led to 72 h correlate release behavior in acidic and physiological pH profiles, while the AgL2-containing nanocomposite showed an analogue behavior for just 6 h and the release of DOX continued and after about 100 h hit the top.

Electrochemical detection of dopamine based on pre-concentration by graphene nanosheets.

Herein, graphene nanosheets (GNS) were synthesized, by a green and facile method based on reduction by glucose, and characterized. Afterwards, a carbon paste electrode (CPE) was modified with GNS by casting and drying GNS on top of the CPE (CPE/GNS). The behavior of the CPE/GNS towards dopamine (DA) and ascorbic acid (AA) was investigated by electrochemical methods and the obtained results showed that the CPE/GNS had adsorbed only DA. Based on this behavior, the DA molecules were pre-concentrated on top of the CPE/GNS, followed by stripping in DA free solution. Subsequent to experimental and instrumental optimization, a calibration curve from 2.0 × 10(-6) to 1.0 × 10(-3) M DA, r(2) = 0.99 (±0.01), with detection limit (DL) = 8.5 × 10(-7) M DA, sensitivity = 15.4 (±0.94) µA, and RSD = 6.1 was observed in the presence of 1.0 × 10(-3) M AA. Finally, the performance of the CPE/GNS was successfully tested in a pharmaceutical sample. This work provides a promising strategy for DA detection in the presence of biological interferences, e.g. AA, with high sensitivity and simple characteristics.

High-Performance Novel MoS2@Zeolite X Nanocomposite-Modified Thin-Film Nanocomposite Forward Osmosis Membranes: A Study of Desalination and Antifouling Performance.

Novel thin-film nanocomposite (TFN) membranes modified by the MoS2@Zeolite X nanocomposite were made and studied for desalination by the forward osmosis (FO) method. Herein, MoS2@Zeolite X nanocomposite (MoS2@Z) and zeolite X particles are integrated into the polyamide (PA) selective layer of the TFN membranes, separately. The aim of this study is the synthesis of nanocomposites containing hydrophilic zeolite X particles with a modified surface and pore and improvement of their effective properties on desalination and antifouling performance. For this purpose, MoS2 nanosheets with a high hydrophilicity were selected. The existence of polymer-matrix-compatible MoS2@Z inside the PA active layer caused the formation of a defect-free smooth surface with further channels within this layer that could increase the water flux and fouling resistance of the TFN membranes. The TFN-MZ2 membrane (containing 0.01 wt % MoS2@Z) showed the top desalination performance in the FO process. In contrast to the pristine thin-film composite (TFC) and TFN-Z2 membrane (containing 0.025 wt % zeolite X, the most optimal membrane among the zeolite-modified membranes), its water flux has increased by 2.6 and 1.8 times, respectively. Furthermore, in the fouling test, this optimal TFN-MZ2 membrane with a flux decrement of 19.6% revealed an ∼2.2- and 1.8-fold enhancement in antifouling tendency compared to the TFC and TFN-Z2, respectively. Also, based on the antibiofouling test, the water flux drop of 48.6% for the TFC membrane has reached 36.9% for the optimal membrane. Hence, this high-performance TFN-MZ2 membrane shows good capability for commercial employment in FO desalination application.

Long-time irradiation effect on corrosion behavior of aluminum alloy in pool water of low-power research reactor.

This study conducted an evaluation of the corrosion behavior of an aluminum alloy utilized in the Isfahan Miniature Neutron Source Reactor (MNSR). The component analyzed, dry channel (DC), had been exposed to radiation for 12 years in a water environment within the reactor pool since its installation. To determine the effect of radiation on the corrosion of the LT-21 aluminum alloy used in the DC, different parts of the pipe were sampled and various tests were performed. These tests included mechanical strengths (impact, and micro-hardening), XRD, TEM, SEM-EDS, and potentiodynamic polarization (PDP). The parameters measured included corrosion potential, corrosion rate, changes in microscopic structure, and mechanical properties of the aluminum alloy along the entire length of the DC. The neutron and gamma dose distribution along the height of the DC, which was 540 cm, was calculated to determine the correlation between the dose distribution and observed corrosion. The study found that the corrosion mechanisms were complex and resulted from the simultaneous presence of the DC in the pool water and radiation from the reactor core. The observed results are presented and discussed in this study.

Impedimetric and potentiometric investigation of a sulfate anion-selective electrode: experiment and simulation.

A new anion-selective polyvinyl chloride (PVC) membrane electrode based on {6,6'-diethoxy-2,2'-[2,2-dimethylpropane-1,3-diylbis(nitrilomethylidyne)]diphenolato}nickel(II)monohydrate as a carrier for the sulfate anion is reported. In this work, a new strategy for optimizing membrane components by electrochemical impedance spectroscopy (EIS) is presented. The performance of this electrode was investigated using potentiometric and EIS techniques. The potentiometric results indicated that the prepared electrode had a Nernstian slope of -28.9 ± 0.1 mV in a linear concentrations range of 1.0 × 10(-6) to 3.0 × 10(-1) M, a detection limit of 6.3 × 10(-7) M, an applied pH range of 4.0-9.0, and a response time of less than 15 s; while using the EIS technique, the linear concentrations range was 1.0 × 10(-9) to 1.0 × 10(-1) M and the pH range increased to 4.0-10.0. Finally, the impedance spectra were simulated using the Maple 13 software. A comparison of the experimental data and information obtained from the simulation confirmed the accuracy of the impedance measurement of this electrode.

Green synthesis of PEG-coated MIL-100(Fe) for controlled release of dacarbazine and its anticancer potential against human melanoma cells.

In this study, the potential of using MIL-100(Fe) metal-organic framework (MOF) for loading and controlling the release of dacarbazine (DTIC) was evaluated for in vitro treatment of melanoma. The drug loading was performed during the green synthesis of MIL-100(Fe) in an aqueous media without using any harmful solvents, to obtain MIL-DTIC. The surface of this structure was then coated with polyethylene glycol (PEG) in the same aqueous solution to synthesize MIL-DTIC-PEG. The synthesized samples were characterized using various methods. Their release profile was studied in phosphate-buffered saline (PBS) and simulated cutaneous medium (SCM). The cytotoxicity of DTIC and its nano-MOF formulation were investigated against melanoma A375 cell lines. The results revealed that the PEG coating (PEGylation) changed the surface charge of MOF from -2.8 ± 0.9 mV to -42.8 ± 1.2 mV, which can contribute to the colloidal stability of MOF. The PEGylation showed a significant effect on controlled drug release, especially in SCM, which increases the complete release time from 60 h to 12 days. Moreover, both of the drug-containing MOFs showed more toxicity than DTIC and unloaded MOFs, confirming that the cumulative release of drug and better cellular uptake of NPs lead to increased toxicity.

Multifunctional green synthesized Cu-Al layered double hydroxide (LDH) nanoparticles: anti-cancer and antibacterial activities.

Doxorubicin (DOX) is a potent anti-cancer agent and there have been attempts in developing nanostructures for its delivery to tumor cells. The nanoparticles promote cytotoxicity of DOX against tumor cells and in turn, they reduce adverse impacts on normal cells. The safety profile of nanostructures is an important topic and recently, the green synthesis of nanoparticles has obtained much attention for the preparation of biocompatible carriers. In the present study, we prepared layered double hydroxide (LDH) nanostructures for doxorubicin (DOX) delivery. The Cu-Al LDH nanoparticles were synthesized by combining Cu(NO3)2·3H2O and Al(NO3)3·9H2O, and then, autoclave at 110. The green modification of LDH nanoparticles with Plantago ovata (PO) was performed and finally, DOX was loaded onto nanostructures. The FTIR, XRD, and FESEM were employed for the characterization of LDH nanoparticles, confirming their proper synthesis. The drug release study revealed the pH-sensitive release of DOX (highest release at pH 5.5) and prolonged DOX release due to PO modification. Furthermore, MTT assay revealed improved biocompatibility of Cu-Al LDH nanostructures upon PO modification and showed controlled and low cytotoxicity towards a wide range of cell lines. The CLSM demonstrated cellular uptake of nanoparticles, both in the HEK-293 and MCF-7 cell lines; however, the results were showed promising cellular internalizations to the HEK-293 rather than MCF-7 cells. The in vivo experiment highlighted the normal histopathological structure of kidneys and no side effects of nanoparticles, further confirming their safety profile and potential as promising nano-scale delivery systems. Finally, antibacterial test revealed toxicity of PO-modified Cu-Al LDH nanoparticles against Gram-positive and -negative bacteria.

Bioactive hybrid metal-organic framework (MOF)-based nanosensors for optical detection of recombinant SARS-CoV-2 spike antigen.

Fast, efficient, and accurate detection of SARS-CoV-2 spike antigen is pivotal to control the spread and reduce the mortality of COVID-19. Nevertheless, the sensitivity of available nanobiosensors to detect recombinant SARS-CoV-2 spike antigen seems insufficient. As a proof-of-concept, MOF-5/CoNi2S4 is developed as a low-cost, safe, and bioactive hybrid nanostructure via the one-pot high-gravity protocol. Then, the porphyrin, H2TMP, was attached to the surface of the synthesized nanomaterial to increase the porosity for efficient detection of recombinant SARS-CoV-2 spike antigen. AFM results approved roughness in different ranges, including 0.54 to 0.74 µm and 0.78 to ≈0.80 µm, showing good physical interactions with the recombinant SARS-CoV-2 spike antigen. MTT assay was performed and compared to the conventional synthesis methods, including hydrothermal, solvothermal, and microwave-assisted methods. The synthesized nanodevices demonstrated above 88% relative cell viability after 24 h and even 48 h of treatment. Besides, the ability of the synthesized nanomaterials to detect the recombinant SARS-CoV-2 spike antigen was investigated, with a detection limit of 5 nM. The in-situ synthesized nanoplatforms exhibited low cytotoxicity, high biocompatibility, and appropriate tunability. The fabricated nanosystems seem promising for future surveys as potential platforms to be integrated into biosensors.