Harnessing the power of Neobacillus niacini AUMC-B524 for silver oxide nanoparticle synthesis: optimization, characterization, and bioactivity exploration.

BACKGROUND: Biotechnology provides a cost-effective way to produce nanomaterials such as silver oxide nanoparticles (Ag2ONPs), which have emerged as versatile entities with diverse applications. This study investigated the ability of endophytic bacteria to biosynthesize Ag2ONPs. RESULTS: A novel endophytic bacterial strain, Neobacillus niacini AUMC-B524, was isolated from Lycium shawii Roem. & Schult leaves and used to synthesize Ag2ONPS extracellularly. Plackett-Burman design and response surface approach was carried out to optimize the biosynthesis of Ag2ONPs (Bio-Ag2ONPs). Comprehensive characterization techniques, including UV-vis spectral analysis, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, dynamic light scattering analysis, Raman microscopy, and energy dispersive X-ray analysis, confirmed the precise composition of the Ag2ONPS. Bio-Ag2ONPs were effective against multidrug-resistant wound pathogens, with minimum inhibitory concentrations (1-25 µg mL-1). Notably, Bio-Ag2ONPs demonstrated no cytotoxic effects on human skin fibroblasts (HSF) in vitro, while effectively suppressing the proliferation of human epidermoid skin carcinoma (A-431) cells, inducing apoptosis and modulating the key apoptotic genes including Bcl-2 associated X protein (Bax), B-cell lymphoma 2 (Bcl-2), Caspase-3 (Cas-3), and guardian of the genome (P53). CONCLUSIONS: These findings highlight the therapeutic potential of Bio-Ag2ONPs synthesized by endophytic N. niacini AUMC-B524, underscoring their antibacterial efficacy, anticancer activity, and biocompatibility, paving the way for novel therapeutic strategies.

Immobilized Drugs on Dual-Mode Imaging Ag2S/BaSO4/PVA Embolic Microspheres for Precise Localization, Rapid Embolization, and Local Antitumor Therapy.

Transcatheter arterial embolization (TAE) in interventional therapy and tumor embolism therapy plays a significant role. The choice of embolic materials that have good biocompatibility is an essential component of TAE. For this study, we produced a multifunctional PVA embolization material that can simultaneously encapsulate Ag2S quantum dots (Ag2S QDs) and BaSO4 nanoparticles (BaSO4 NPs), exhibiting excellent second near-infrared window (NIR-II) fluorescence imaging and X-ray imaging, breaking through the limitations of traditional embolic microsphere X-ray imaging. To improve the therapeutic effectiveness against tumors, we doped the doxorubicin (DOX) antitumor drug into microspheres and combined it with a clotting peptide (RADA16-I) on the surface of microspheres. Thus, it not only embolizes rapidly during hemostasis but also continues to release and accelerate tumor necrosis. In addition, Ag2S/BaSO4/PVA microspheres (Ag2S/BaSO4/PVA Ms) exhibited good blood compatibility and biocompatibility, and the results of embolization experiments on renal arteries in rabbits revealed good embolic effects and bimodal imaging stability. Therefore, they could serve as a promising medication delivery embolic system and an efficient biomaterial for arterial embolization. Our research work achieves the applicability of NIR-II and X-ray dual-mode images for clinical embolization in biomedical imaging.

Structural engineering of mitochondria-targeted Au-Ag2S photosensitizers for enhanced photodynamic and photothermal therapy.

Much effort has been devoted to designing diverse photosensitizers for efficient photodynamic therapy (PDT) and photothermal therapy (PTT) performance. However, the effect of PS morphology on the PDT and PTT performance needs to be further explored. In this work, a photosensitizer, Au-Ag2S nanoparticles functionalized with indocyanine green, caspase-3 recognition peptides, and mitochondria-targeting peptides (AICM NPs) with different morphologies, including core-shell, eccentric core-shell-I, eccentric core-shell-II, and Janus morphologies, were synthesized to enhance PDT and PTT performance. Among them, AICM Janus NPs with enhanced charge-transfer efficiency and photothermal conversion demonstrate superior PDT and PTT performance compared to those of other morphologies. In addition, AICM NPs exhibit satisfactory surface-enhanced Raman scattering performance for in situ SERS monitoring of caspase-3 during PDT and PTT processes. After PDT and PTT treatment with AICM Janus NPs, the damaged mitochondria released caspase-3. AICM Janus NPs achieved a superior apoptosis rate in tumor cells in vitro. Furthermore, AICM Janus NPs treat the tumors in vivo within only 10 days, which is half the time reported in other work. The AICM NPs demonstrated superior therapeutic safety both in vitro and in vivo. This study investigates the effects of morphology-property-performance of photosensitizers on the PDT and PTT performances, which opens a new pathway toward designing photosensitizers for efficient PDT and PTT.

Molecularly imprinted Ag2S quantum dots with high photocatalytic activity for dye removal: Experimental and DFT insights.

Molecular imprinted polymers (MIPs) were developed by carrying out the cocktail solution of Template ((Salata, 2004)-Gingerol), monomer, crosslinker, and Ag2S Quantum Dots (QDs) by ex-situ dissolved in an appropriate solvent, resulting in an efficient crosslinked polymer composite. Degradation of Alizarin red S (ARS) dye and yellowish sunset (SY) azo dye under visible light irradiation was reported first time by the introduction of prepared MIPs composite. In this research, the result shows efficient photocatalyt activity of Ag2S-MIPs composite for the degradation of AR and SY dye with degradation% (80%) and (84%) in the aqueous wastewater. The degradation efficiency of the Ag2S-MIPs composite and the Ag2S QD associated with non-imprinted polymers (NIPs) (i.e.Ag2S-NIPs composite) were calculated by using different parameters such as catalyst dose, pH value, optimum time and concentration variation and the observations are evocative. Moreover, the density functional theory (DFT) approach was also used to analyze the structural, stability/energetics, and electronic features of the organic-inorganic hybrid composites of the Ag2S QD with the MIPs based on (Salata, 2004)-gingerol extract. The proposed QD and MIPs (EGDMA and (Salata, 2004)-Gingerol) composite model has been detected to be the most stable because it shows the largest binding energy (BE) among the three chosen composite models. It was found out that imprinted polymers were superior in enhancing the degradation of dyes when compared to non imprinted polymers. Introducing MIPs into the valence band accelerates the catalysis properties to stabilize newly fashioned excitons that are basically generated as a result of light excitation in presence of Ag2S Quantum Dots (QDs) and molecular imprinted polymer (MIPs). Motivation behind this work is to address the challenges related to environmental pollution causing by organic dyes. These toxins are known to cause diverse symptoms (e.g., skin irritation, eye infection, respiratory disorders, and even cancer) once exposed through ingestion and inhalation. Through incorporation of Ag2S QD into MIP,the purpose of this research is to enhance the selectivity, specificity and photocatalytic activity for dyes and that work holds a potential towards environmental remediation by developing a cost effective and sustainable method for controlling pollution in water.

Visualization of 2D and 3D Tissue Models via Size-Selected Aqueous AgInS/ZnS Quantum Dots.

Three-dimensional (3D) spheroid cell cultures of fibroblast (L929) and tumor mammary mouse (4T1) were chosen as in vitro tissue models for tissue imaging of ternary AgInS/ZnS fraction quantum dots (QDs). We showed that the tissue-mimetic morphology of cell spheroids through well-developed cell-cell and cell-matrix interactions and distinct diffusion/transport characteristics makes it possible to predict the effect of ternary AgInS/ZnS fraction QDs on the vital activity of cells while simultaneously comparing with classical two-dimensional (2D) cell cultures. The AgInS/ZnS fractions, emitting in a wide spectral range from 635 to 535 nm with a mean size from ∼3.1 ± 0.8 to ∼1.8 ± 0.4 nm and a long photoluminescence lifetime, were separated from the initial QD ensemble by using antisolvent-induced precipitation. For ternary AgInS/ZnS fraction QDs, the absence of toxicity at different QD concentrations was demonstrated on 2D and 3D cell structures. QDs show a robust correlation between numerous factors: their sizes in biological fluids over time, penetration capabilities into 2D and 3D cell structures, and selectivity with respect to penetration into cancerous and healthy cell spheroids. A reproducible protocol for the preparation of QDs along with their unique biological properties allows us to consider ternary AgInS/ZnS fraction QDs as attractive fluorescent contrast agents for tissue imaging.

Sonochemical synthesis of graphene oxide-Ag2O nanozyme as an oxidize-like mimic for the highly sensitive detection of lithium in blood serum.

Bipolar disorder is commonly treated with lithium carbonate. The concentration of lithium in the blood serum should be closely monitored in patients who require long-term lithium therapy. To date, no colorimetric method of detecting lithium ions has been reported using nanosensors. We have developed a novel chemosensor based on nanozyme (NZ) to address this clinical need. The GO-Ag2O NZs were synthesized by a sonochemical method and used as a colorimetric nanosensor to detect lithium ions in human blood serum (Li (I)). To characterize NZs, various techniques were employed, including XRD, FTIR, TEM, FESEM, EDX, Raman spectroscopy, BET, DLS, Zeta potential, and ICP-OES. According to TEM and FESEM images of GO-Ag2O, the nanoparticles (NPs) of Ag2O are uniformly distributed on the surface of 2D graphene oxide sheets. In addition, silver oxide nanoparticles exhibited a cubic morphology with an average size of 3.5 nm. We have examined the performance of the NZs in an aqueous medium and in human blood serum that contains Li (I). A colorimetric test revealed that NZs synthesized in the presence of ultrasound were more sensitive to Li (I). According to the linearity of the calibration curves' ranges, Li (I) has a limit of detection (LOD) of 0.01 µg/mL. Furthermore, it displayed a linear range between 0 and 12 µg/mL. GO-Ag2O NZs showed noticeable color changes from green to orange after exposure to Li (I). An incubation time of two minutes was found to be the most effective for sensing. This innovative approach provides a reliable method for monitoring lithium levels and ensuring patient safety during long-term lithium therapy for bipolar disorder.

Green hydrothermal synthesis and characterization of Ag2O-supported MgO/rGO nanocomposites by using Phoenix leaf extract: a promising approach for enhanced photocatalytic and anticancer activities.

The present work was designed to synthesize Ag2O-supported MgO/rGO nanocomposites (NCs) via green method using Phoenix leaf extract for improved photocatalytic and anticancer activity. Green synthesized Ag2O-supported MgO/rGO NCs were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Raman, ultraviolet-visible (UV-vis) spectroscopy, and photoluminescence (PL) spectroscopy, and gas chromatography-mass spectroscopy (GC-MS) was applied to examine the chemical components of the Phoenix leaf extract. Characterization data confirmed the preparation of MgO NPs, Ag2O-MgO NCs, and Ag2O-MgO/rGO NC with particle size of 26-28 nm. UV-vis study exhibited that the band gap energy of MgO NPs, Ag2O-MgO NCs, and Ag2O-MgO/rGO NC were in the range of 3.53-3.43 eV. The photocatalytic results showed that the photodegradation of Rh B dye of Ag2O-supported MgO/rGO NCs (82.81%) was significantly higher than pure MgO NPs. Additionally, the biological response demonstrates that the Ag2O-supported MgO/rGO NCs induced high cytotoxicity against MCF-7 cancer cells for 24 h and 48 h compared with both pure MgO NPs and Ag2O-MgO NCs. This study suggests that the adding of Ag2O and rGO sheets played significant role in the enhanced photocatalytic and anticancer performance of MgO NPs.

Antiviral Activity of Ag5IO6, a Unique Silver Compound.

Pentasilver hexaoxoiodate (Ag5IO6) has broad-spectrum antimicrobial efficacy, including the long-term prevention of microbial adherence, the rapid killing of planktonic microorganisms, and the elimination of mature biofilms. This study's goal was to determine whether it may also have antiviral activity against structurally distinct viruses. Ag5IO6 was tested following ASTM E1052-20, Standard Practice to Assess the Activity of Microbicides Against Viruses in Suspension, against adenovirus type 5, murine norovirus, poliovirus type 1, SARS-CoV-2 (original), and SARS-CoV-2 (omicron) (host cells: H1HeLa, RAW 264.7, LLC-MK2, Vero E6, and Vero E6, respectively). A 0.1 g/mL Ag5IO6 suspension was prepared and the viruses were exposed for 30 min, 4 h, or 24 h. Exposure to Ag5IO6 resulted in complete kill of SARS-CoV-2 (omicron) within 30 min, as well as complete kill of both SARS-CoV-2 (original) and the murine norovirus within 4 h. Ag5IO6 showed increasing activity over time against the adenovirus, but did not achieve a 3-log reduction within 24 h, and showed no antiviral activity against the poliovirus. These results demonstrate that Ag5IO6 has antiviral activity against medically important viruses, in addition to its well-characterized antimicrobial activity, suggesting that it may be valuable in situations where the prevention or simultaneous treatment of microbes and viruses are necessary.

Acid-Triggered Degradation of Three-In-One Ag2S Quantum Dots for In Situ Ratiometric NIR-II Fluorescence Imaging-Guided Ion/Gas Combination Therapy.

Smart theranostic nanoprobes with the integration of multiple therapeutic modalities are preferred for precise diagnosis and efficient therapy of tumors. However, it remains a big challenge to arrange the imaging and two or more kinds of therapeutic agents without weakening the intended performances. In addition, most existing fluorescence (FL) imaging agents suffer from low spatiotemporal resolution due to the short emission wavelength (<900 nm). Here, novel three-in-one Ag2S quantum dot (QD)-based smart theranostic nanoprobes were proposed for in situ ratiometric NIR-II FL imaging-guided ion/gas combination therapy of tumors. Under the acidic tumor microenvironment, three-in-one Ag2S QDs underwent destructive degradation, generating toxic Ag+ and H2S. Meanwhile, their FL emission at 1270 nm was weakened. Upon introduction of a downconversion nanoparticle (DCNP) as the delivery carrier and NIR-II FL reference signal unit, the formed Ag2S QD-based theranostic nanoprobes could achieve precise diagnosis of tumors through ratiometric NIR-II FL signals. Also, the generated Ag+ and H2S enabled specific ion/gas combination therapy toward tumors. By combining the imaging and therapeutic functions, three-in-one Ag2S QDs may open a simple yet reliable avenue to design theranostic nanoprobes.

Versatile Metal-Organic Framework Incorporating Ag2S for Constructing a Photoelectrochemical Immunosensor for Two Breast Cancer Markers.

Breast cancer poses the significance of early diagnosis and treatment. Here, we developed an innovative photoelectrochemical (PEC) immunosensor characterized by high-level dual photocurrent signals and exceptional sensitivity. The PEC sensor, denoted as MIL&Ag2S, was constructed by incorporating Ag2S into a metal-organic framework of MIL-101(Cr). This composite not only enhanced electron-hole separation and conductivity but also yielded robust and stable dual photocurrent signals. Through the implementation of signal switching, we achieved the combined detection of cancer antigen 15-3 (CA15-3) and carcinoembryonic antigen (CEA) with outstanding stability, reproducibility, and specificity. The results revealed a linear range for CEA detection spanning 0.01-32 ng/mL, with a remarkably low detection limit of 0.0023 ng/mL. Similarly, for CA15-3 detection, the linear range extended from 0.1 to 320 U/mL, with a low detection limit of 0.014 U/mL. The proposed strategy introduces new avenues for the development of highly efficient, cost-effective, and user-friendly PEC sensors. Furthermore, it holds promising prospects for early clinical diagnosis, contributing to potential breakthroughs in medical detection and ultimately improving patient outcomes.

Biogenic synthesis, characterization, and in vitro biological investigation of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata.

The current research aimed to study the green synthesis of silver oxide nanoparticles (AgONPs) using Rhynchosia capitata (RC) aqueous extract as a potent reducing and stabilizing agent. The obtained RC-AgONPs were characterized using UV, FT-IR, XRD, DLS, SEM, and EDX to investigate the morphology, size, and elemental composition. The size of the RC-AgONPs was found to be ~ 21.66 nm and an almost uniform distribution was executed by XRD analysis. In vitro studies were performed to reveal biological potential. The AgONPs exhibited efficient DPPH free radical scavenging potential (71.3%), reducing power (63.8 ± 1.77%), and total antioxidant capacity (88.5 ± 4.8%) to estimate their antioxidative power. Antibacterial and antifungal potentials were evaluated using the disc diffusion method against various bacterial and fungal strains, and the zones of inhibition (ZOI) were determined. A brine shrimp cytotoxicity assay was conducted to measure the cytotoxicity potential (LC50: 2.26 µg/mL). In addition, biocompatibility tests were performed to evaluate the biocompatible nature of RC-AgONPs using red blood cells, HEK, and VERO cell lines (< 200 µg/mL). An alpha-amylase inhibition assay was carried out with 67.6% inhibition. Moreover, In vitro, anticancer activity was performed against Hep-2 liver cancer cell lines, and an LC50 value of 45.94 µg/mL was achieved. Overall, the present study has demonstrated that the utilization of R. capitata extract for the biosynthesis of AgONPs offers a cost-effective, eco-friendly, and forthright alternative to traditional approaches for silver nanoparticle synthesis. The RC-AgONPs obtained exhibited significant bioactive properties, positioning them as promising candidates for diverse applications in the spheres of medicine and beyond.

Polyvalent Aptamer-Functionalized NIR-II Quantum Dots for Targeted Theranostics in High PD-L1-Expressing Tumors.

Ag2S quantum dots (QDs) show superior optical properties in the NIR-II region and display significant clinical potential with favorable biocompatibility. However, inherent defects of low targeting and poor solubility necessitate practical modification methods to achieve the theranostics of Ag2S QDs. Herein, we used rolling circle amplification (RCA) techniques to obtain long single-stranded DNA containing the PD-L1 aptamer and C-rich DNA palindromic sequence. The C-rich DNA palindromic sequences can specifically chelate Ag2+ and thus serve as a template to result in biomimetic mineralization and formation of pApt-Ag2S QDs. These QDs enable specific targeting and illuminate hot tumors with high PD-L1 expression effectively, serving as excellent molecular targeted probes. In addition, due to the high NIR-II absorption of Ag2S QDs, pApt-Ag2S QDs exhibit remarkable photothermal properties. And besides, polyvalent PD-L1 aptamers can recognize PD-L1 protein and effectively block the inhibitory signal of PD-L1 on T cells, enabling efficient theranostics through the synergistic effect of photothermal therapy and immune checkpoint blocking therapy. Summary, we enhance the biological stability and antibleaching ability of Ag2S QDs using long single-stranded DNA as a template, thereby establishing a theranostic platform that specifically targets PD-L1 high-expressing inflamed tumors and demonstrates excellent performance both in vitro and in vivo.

Biosynthesis of NIR-II Ag2Se Quantum Dots with Bacterial Catalase for Photoacoustic Imaging and Alleviating-Hypoxia Photothermal Therapy.

Developing the second near-infrared (NIR-II) photoacoustic (PA) agent is of great interest in bioimaging. Ag2Se quantum dots (QDs) are one kind of potential probe for applications in NIR-II photoacoustic imaging (PAI). However, the surfaces with excess anions of Ag2Se QDs, which increase the probability of nonradiative transitions of excitons benefiting PA imaging, are not conducive to binding electron donor ligands for potential biolabeling and imaging. In this study, Staphylococcus aureus (S. aureus) cells are driven for the biosynthesis of Ag2Se QDs with catalase (CAT). Biosynthesized Ag2Se (bio-Ag2Se-CAT) QDs are produced in Se-enriched environment of S. aureus and have a high Se-rich surface. The photothermal conversion efficiency of bio-Ag2Se-CAT QDs at 808 and 1064 nm is calculated as 75.3% and 51.7%, respectively. Additionally, the PA signal responsiveness of bio-Ag2Se-CAT QDs is ≈10 times that of the commercial PA contrast agent indocyanine green. In particular, the bacterial CAT is naturally attached to bio-Ag2Se-CAT QDs surface, which can effectively relieve tumor hypoxia. The bio-Ag2Se-CAT QDs can relieve heat-initiated oxidative stress while undergoing effective photothermal therapy (PTT). Such biosynthesis method of NIR-II bio-Ag2Se-CAT QDs opens a new avenue for developing multifunctional nanomaterials, showing great promise for PAI, hypoxia alleviation, and PTT.

Enhancing oil-water emulsion separation via synergistic filtration using graphene oxide-silver oxide nanocomposite-embedded polyethersulfone membrane.

This study introduces an innovative approach for enhancing oil-water emulsion separation using a polyethersulfone (PES) membrane embedded with a nanocomposite of graphene oxide (GO) and silver oxide (AgO). The composite membrane, incorporating PES and polyvinyl chloride (PVC), demonstrates improved hydrophilicity, structural integrity and resistance to fouling. Physicochemical characterization confirms successful integration of GO and AgO, leading to increased tensile strength, porosity and hydrophilicity. Filtration tests reveal substantial improvements in separating various oils from contaminated wastewater, with the composite membrane exhibiting superior efficiency and reusability compared to pristine PES membranes. This research contributes to the development of environmentally friendly oil-water separation methods with broad industrial applications.

Phase Engineered CuxS-Ag2S with Photothermoelectric Activity for Enhanced Multienzyme Activity and Dynamic Therapy.

The insufficient exposure sites and active site competition of multienzyme are the two main factors to hinder its therapeutic effect. Here, a phase-junction nanomaterial (amorphous-crystalline CuxS-Ag2S) is designed and prepared through a simple room temperature ion-exchange process. A small amount of Ag+ is added into Cu7S4 nanocrystals, which transforms Cu7S4 into amorphous phased CuxS and produces crystalline Ag2S simultaneously. In this structure, the overhanging bonds on the amorphous CuxS surface provide abundant active sites for optimizing the therapeutic activity. Meanwhile, the amorphous state enhances the photothermal effect through non-radiative relaxation, and due to its low thermal resistance, phase-junction CuxS-Ag2S forms a significant temperature gradient to unlock the optimized thermo-electrodynamic therapy. Furthermore, benefiting from the high asymmetry of the amorphous state, the material forms a spin-polarized state that can effectively inhibit electron-hole recombination. In this way, the thermoelectric effect can facilitate the enzyme-catalyzed cycle by providing electrons and holes, enabling an enhanced coupling of thermoelectric therapy with multienzyme activity, which induces excellent anti-tumor performance. More importantly, the catalytic process simulated by density-functional theory proves that Ag+ alleviates the burden on the Cu sites through favorable adsorption of O2 and prevents active site competition.

A versatile technique based on surface-enhanced Raman spectroscopy for label-free detection of amino acids and peptide formation in body fluids.

As an effective analytical method, surface-enhanced Raman spectroscopy (SERS) is widely used in the detection of nucleic acids, amino acids, and other biomolecules. However, obtaining the SERS signal of nonaromatic amino acids is still a challenge. In this work, excess sodium borohydride was used as a reducing agent to prevent the surface of silver nanoparticles from being coated with AgO to enable amino acid molecules to reach the surface of silver nano-substrates. Calcium ions were used as aggregators for silver nano-substrates to successfully achieve the label-free and accurate fingerprint determination of various nonaromatic amino acids. Different types of amino acids were distinguished based on the changes in their peak intensity that were obtained using colorless and transparent organic dichloromethane (DCM) as the internal standard. A Raman signal for low-concentration amino acids in body fluids was detected, and the detection limit for tyrosine was 5 ng/mL. Moreover, the physical and chemical properties of peptides and the formation of peptide chains were further analyzed. The proposed method can potentially be applied to protein sequencing.

Photochromic immunoassay for tumor marker detection based on ZnO/AgI nanophotocatalyst.

A photochromic immunoassay was built for tumor marker detection based on ZnO/AgI nanophotocatalyst. Frist, ZnO/AgI nanoparticles were synthesized and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectrometry (FTIR). The color development is caused by tetramethyl benzidine (TMB) solution oxidated by ZnO/AgI nanomaterials. The electron transitions in ZnO/AgI nanomaterials are driven by visible light irradiation, generating photogenerated hole and oxidizing TMB to blue solution. Appropriate band width between ZnO and AgI promotes separation of photogenerated electrons and holes and enhances oxidation efficiency. A sandwich-type immunoassay was constructed based on ZnO/AgI nanomaterial as labels. The absorbance at 650 nm of reaction solution is positively correlated with antigen concentration. The developed immunoassay showed good performance for carcinoma embryonic antigen (CEA) detection in the range 0.1-7.0 ng/mL with a detection limit of 65 pg/mL. The photochromic immunoassay also exhibited preferable selectivity, repeatability, and stability. A novel colorimetric immunoassay was constructed based on ZnO/AgI photocatalyst. ZnO/AgI nanomaterials occur electron transitions under visible light irradiation and generate photogenerated hole, which can oxidize TMB to blue solution. Carcinoembryonic antigen in sample was detected sensitively due to the high catalytic efficiency of ZnO/AgI nanomaterials.

Octahedral silver oxide nanoparticles enabling remarkable SERS activity for detecting circulating tumor cells.

The detection of circulating tumor cells (CTCs) is a crucial tool for early cancer diagnosis, prognosis, and postoperative evaluation. However, detection sensitivity remains a major challenge because CTCs are extremely rare in peripheral blood. To effectively detect CTCs, octahedral Ag2O nanoparticles (NPs) with high dispersibility, good biocompatibility, remarkable surface-enhanced Raman scattering (SERS) enhancement, and obvious enhancement selectivity are designed as an SERS platform. Ag2O NPs with many oxygen vacancy defects are successfully synthesized, which exhibit an ultra-high SERS enhancement factor (1.98×106) for 4-mercaptopyridine molecules. The remarkable SERS activity of octahedral Ag2O NPs is derived from the synergistic effect of the surface defect-promoted photo-induced charge transfer (PICT) process and strong vibration coupling resonance in the Ag2O-molecule SERS complex, greatly amplifying the molecular Raman scattering cross-section. The promoted PICT process is confirmed using ultraviolet-visible (UV-Vis) absorption spectroscopy, demonstrating that obvious PICT resonance occurs in Ag2O SERS system under visible light. An additional growth step of SERS bioprobe is proposed by modifying the Raman signal molecules and functional biological molecules on Ag2O NPs for CTC detection. The Ag2O-based SERS bioprobe exhibits excellent detection specificity for different cancer cells in rabbit blood. Importantly, the high-sensitivity Ag2O-based SERS bioprobe satisfies the requirement for rare CTC detection in the peripheral blood of cancer patients, and the detection limit can reach 1 cell per mL. To our knowledge, this study is the first time that a semiconductor SERS substrate has been successfully utilized in CTC detection. This work provides new insights into CTC detection and the development of novel semiconductor-based SERS platforms for cancer diagnosis.

Biosynthesis of silver nanoparticles from Mukia maderaspatana (L) and their biological activities.

Nanotechnology is a field of science that consists of atoms, molecules and supramolecular molecules that create nanoparticles ranging in size from 1-100nm. Silver nanoparticles are widely used that are considered as effective antimicrobial agents. In this paper, the antioxidant activity of biosynthesized SNPs were analyzed by the DPPPH activity, hydrogen peroxide activity, hydroxyl RSA, TAC, TFC; their results confirmed that the phenolic compounds of this plant peels extracts enhanced the antioxidant and antiglycation activity with respect to silver nanoparticles. Biosynthesized nanoparticles of this plant extracts also showed strong zone of inhibition against the different Xanthomas, Pseudomonas and E. coli. This study concluded that biosynthesized nanoparticles of Mukia maderaspatna (M.M) plant peels extracts have the great biological activities i.e. antiglycation, antioxidant and antibacterial. More research is needed to know the exact dose rate and to compare the different dose combination of the plant with the strong antibiotic agents against these bacteria.

Mycofabrication of AgONPs derived from Aspergillus terreus FC36AY1 and its potent antimicrobial, antioxidant, and anti-angiogenesis activities.

BACKGROUND: There is an emergency need for the natural therapeutic agents to treat arious life threatening diseases such as cardio- vascular disease, Rheumatoid arthritis and cancer. Among these diseases, cancer is found to be the second life threatening disease; in this view the present study focused to synthesize the silver oxide nanoparticles (AgONPs) from endophytic fungus. METHODS: The endophytic fungus was isolated from a medicinal tree Aegle marmelos (Vilva tree) and the potential strain was screened through antagonistic activity. The endophytic fungus was identified through microscopic (Lactophenol cotton blue staining and spore morphology in culture media) and Internal Transcribed Spacer (ITS) 1, ITS 4 and 18S rRNA amplification. The endophyte was cultured for the synthesis of AgONPs and the synthesized NPs were characterized through UV- Vis, FT- IR, EDX, XRD and SEM. The synthesized AgONPs were determined for antimicrobial, antioxidant and anti- angiogenic activity. RESULTS: About 35 pigmented endophytic fungi were isolated, screened for antagonistic activity against 12 pathogens and antioxidant activity through DPPH radical scavenging assay; among the isolates, FC36AY1 explored the highest activity and the strain FC36AY1 was identified as Aspergillus terreus. The AgONPs were synthesized from the strain FC36AY1 and characterized for its confirmation, functional groups, nanostructures with unit cell dimensions, size and shape, presence of elements through UV-Vis spectrophotometry, FT-IR, XRD, SEM with EDX analysis. The myco-generated AgONPs manifested their antimicrobial and antioxidant properties with maximum activity at minimum concentration. Moreover, the inhibition of angiogenesis by the AgONPs in Hen's Egg Test on the Chorio-Allantoic Membrane analysis were tested on the eggs of Chittagong breed evinced at significant bioactivity least concentration at 0.1 µg/mL. CONCLUSIONS: Thus, the results of this study revealed that the fungal mediated AgONPs can be exploited as potential in biomedical applications.