Development of a FRET aptasensor based on MoS2-doped Zn-MOF as luminophore for selective detection of cadmium in aqueous solutions.

A robust "on-off" fluorescent aptasensor was developed using nanohybrids of molybdenum sulfide (MoS2) quantum dot (QD)-doped zinc metal-organic frameworks (Zn-MOF) for selective and sensitive detection of cadmium ions (Cd2+) in water. This nanohybrid (MoS2@Zn-MOF), synthesized via "bottle around the ship" methodology, exhibited a high-intensity fluorescence emission centered at 430 nm (λEm) (blue) on excitation at 320 nm (λEx). Further, the conjugation of this fluorophore to phosphate-modified cadmium aptamer (Cd-2-2) was achieved through carbodiimide reaction. The hybridization of prepared sensing probe (MoS2@Zn-MOF/Cd-2-2 aptamer) was done with dabcyl-conjugated complementary DNA (cDNA), acting as energy donor-acceptor pair in the fluorescence resonance energy transfer (FRET) system. This hybridization causes the fluorescence quenching of the nanohybrid. In the presence of Cd2+, the aptamer from the fabricated nano-biosensing probe binds to these ions, resulting in release of dabcyl-cDNA oligomer. This release of dabcyl-cDNA oligomer from the sensing probes restores the fluorescence of the nanohybrid. Under optimized conditions (sensing probe/dabcyl-cDNA ratio 1/7, pH 7.4, and temp 28 °C), the sensing probe showed a fast response time of 1 min. The fluorescence intensity of the nanohybrid can be utilized to determine the concentration of Cd2+. The proposed aptasensor achieved highly sensitive detection of Cd2+ with a limit of detection (LOD) of 0.24 ppb over the range of 1 × 10-9 to 1 × 10-4 M along with minimal effects of interferences (e.g., Hg2+, Pb2+, and Zn2+) and good reproducibility. The designed aptasensor based on MoS2@Zn-MOF nanofluorophore offers a highly sensitive and selective approach for rapid screening of metal ions in aqueous environments.

Antibacterial Activity of Sustainable Thymol Nanoemulsion Formulations Against the Bacterial Blight Disease on Cluster Bean Caused by Xanthomonas axonopodis.

The aim of the present study was nanoencapsulation of thymol to improve its poor water solubility and preservation of encapsulated thymol against environmental conditions. Another goal of the current investigation was to assess the antibacterial activity of thymol nanoemulsion as a sustainable biopesticide to control the bacterial blight of cluster bean. An oil-in-water (o/w) nanoemulsion containing thymol was prepared by a high-energy emulsification method using gum acacia and soya lecithin as natural emulsifiers/surfactants. The characterization of thymol nanoemulsion was carried out using dynamic light scattering (DLS), transmission electron microscope (TEM) and Fourier transform infrared spectroscopy (FTIR). A mean particle size of about 83.38 nm was recorded within 10 min of sonication. The stability analysis of optimized nanoemulsion showed kinetic stability up to two months of storage at room temperature. The thymol nanoemulsion was found to be spherical with a size ranging from 80-200 nm in diameter using transmission electron microscopy. Fourier transform infrared spectroscopy was used to study the molecular interaction between emulsifier/surfactant and thymol. The antibacterial studies of thymol nanoemulsion (0.01-0.06%, v/v) by growth inhibition analysis showed a potential antibacterial effect against Xanthomonas axonopodis pv. cyamopsidis (18-0.1 log CFU/ml). Further, in field experiments, foliar spray of the different concentration of thymol nanoemulsion (0.01-0.06%, v/v) significantly increased the percent efficiency of disease control (25.06-94.48%) and reduced the disease intensity (67.33-4.25%) of bacterial blight in cluster bean.

Advanced Selection Methodologies for DNAzymes in Sensing and Healthcare Applications.

DNAzymes have been widely explored owing to their excellent catalytic activity in a broad range of applications, notably in sensing and biomedical devices. These newly discovered applications have built high hopes for designing novel catalytic DNAzymes. However, the selection of efficient DNAzymes is a challenging process but one that is of crucial importance. Initially, systemic evolution of ligands by exponential enrichment (SELEX) was a labor-intensive and time-consuming process, but recent advances have accelerated the automated generation of DNAzyme molecules. This review summarizes recent advances in SELEX that improve the affinity and specificity of DNAzymes. The thriving generation of new DNAzymes is expected to open the door to several healthcare applications. Therefore, a significant portion of this review is dedicated to various biological applications of DNAzymes, such as sensing, therapeutics, and nanodevices. In addition, discussion is further extended to the barriers encountered for the real-life application of these DNAzymes to provide a foundation for future research.

Current paradigms in epigenetic anticancer therapeutics and future challenges.

Any alteration at the genetic or epigenetic level, may result in multiplex of diseases including tumorigenesis which ultimately results in the cancer development. Restoration of the normal epigenome by reversing the epigenetic alterations have been reported in tumors paving the way for development of an effective epigenetic treatment in cancer. However, delineating various epigenetic events has been a challenging task so far despite substantial progress in understanding DNA methylation and histone modifications during transcription of genes. Many inhibitors in the form of epigenetic drugs mostly targeting chromatin and histone modifying enzymes including DNA methyltransferase (DNMT) enzyme inhibitors and a histone deacetylases (HDACs) inhibitor, have been in use subsequent to the approval by FDA for cancer treatment. Similarly, other inhibitory drugs, such as FK228, suberoylanilide hydroxamic acid (SAHA) and MS-275, have been successfully tested in clinical studies. Despite all these advancements, still we see a hazy view as far as a promising epigenetic anticancer therapy is concerned. The challenges are to have more specific and effective inhibitors with negligible side effects. Moreover, the alterations seen in tumors are not well understood for which one has to gain deeper insight into the tumor pathology as well. Current review focusses on such epigenetic alterations occurring in cancer and the effective strategies to utilize such alterations for potential therapeutic use and treatment in cancer.

Radon and thoron exhalation rate in the soil of Western Haryana, India.

This study reports the exhalation rates of radon and thoron from surface soil collected from 60 rural sites of district Hisar, Haryana, India. The exhalation rates of Rn222 (radon) and Rn220 (thoron) were measured by portable SMART RnDuo (AQTEK SYSTEMS) using a mass accumulation chamber which was equipped with a scintillation material-coated cell. Dose rates due to natural gamma radiations ranged from 0.526 to 1.139 mSv y-1. The Rn222 mass exhalation rate in soil samples varied from 0.14 to 94.65 mBq kg-1 h-1. Thoron surface exhalation rates ranged from 46.42 to 619.88 Bq m-2 h-1. This study gives an idea about the differences in Rn222 and Rn220 exhalation at different locations which may be due to variations in geological features of the locations and characteristics of the topsoil. The findings show that usage of study area soil as building material is safe.

Sn-MOF@CNT nanocomposite: An efficient electrochemical sensor for detection of hydrogen peroxide.

A novel approach for the assembly of Sn-based metal organic framework (Sn-MOF) via solvothermal method and its composite (Sn-MOF@CNT) with electroactive material, carbon nanotubes (CNT) by sonochemical means, is described that is useful for hydrogen peroxide sensing; large surface area and pore volume of Sn-MOF were exploited where in the crystallinity of the Sn-MOF was preserved upon inclusion of CNT over its surface. The surface morphology and structural analysis of Sn-MOF and its composite form, Sn-MOF@CNT, were determined analytically through Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller and Energy-dispersive X-ray spectroscopy (EDX). The developed Sn-MOF@CNT sensor was expansively used to determine and optimize the effect of scan rate, concentration and detection limits including the EDX and SEM analysis of used Sn-MOF@CNT nanocomposite's post hydrogen peroxide sensing. The electrochemical sensing with Sn-MOF@CNT revealed a lower limit of detection ~4.7 × 10-3 µM with wide linear range between 0.2 µM and 2.5 mM. This study has explored a new strategy for the deposition of CNT over Sn-MOF via a simple sonochemical methodology for successful electrochemical detection of H2O2, an approach that can be imitated for other applications.

Carbonaceous nanomaterials as effective and efficient platforms for removal of dyes from aqueous systems.

In this study, the feasibility of using carbonaceous nanomaterials was explored for adsorptive removal of methylene blue (MB) and methyl orange (MO) dyes from contaminated water under dark conditions. The morphology and crystalline nature of synthesized carbonaceous nanomaterials (e.g., multi-walled carbon nanotubes [MWCNTs], activated carbon [AC], and their nanocomposite) were characterized by different microscopic and spectroscopic techniques. Furthermore, adsorption experiments were carried out by controlling several key parameters including solution pH, adsorbent dosage, dye concentration, contact time, and temperature. First, the adsorptive behavior of MWCNTs was explained with the aid of adsorption isotherms and kinetics. Thereafter, the adsorptive performance of MWCNTs was compared with those of AC and MWCNTs/AC, and the maximum adsorption capacity (mg/g) of MB/MO was in the order of MWCNTs/AC nanocomposite (232.5/196.1) > MWCNTs (185.1/106.3) > AC (161.3/78.7). The improved adsorption performance (e.g., in terms of adsorption capacity and partition coefficient) of the MWCNTs/AC nanocomposite could be attributed to the presence of more active sites on its surface. Furthermore, their reusable efficiency was in the order of MWCNTs/AC nanocomposite (90.2%), MWCNTs (81%), and AC (67%) after the first step of recovery. The performance of these adsorbents was also evaluated for real field samples. In comparison to MWCNTs and AC, the MWCNTs/AC sorbents offered excellent performance in both single and binary systems, i.e., ~99.8% and 98.7% average removal of MB and MO, respectively.

Investigating the efficiency of α-Bismuth zinc oxide heterostructure composite/UV-LED in methylene blue dye removal and evaluation of its antimicrobial activity.

Heterostructured α-Bismuth zinc oxide (α-Bi2O3-ZnO) photocatalyst was fabricated by a facile and cost-effective, ultrasound assisted chemical precipitation method followed by hydrothermal growth technique. As synthesized α-Bi2O3-ZnO photocatalyst showed enhanced photocatalytic performance for the MB dye degradation in contrast to pure ZnO and α-Bi2O3. Light emitting diodes (UV-LED) were used in the experimental setup, which has several advantages over conventional lamps like wavelength selectivity, high efficacy, less power consumption, long lifespan, no disposal problem, no warming-up time, compactness, easy and economic installation. XRD study confirmed the presence of both the lattice phases i.e. monoclinic and hexagonal wurtzite phase corresponding to α-Bi2O3 and ZnO in the α-Bi2O3-ZnO composite photocatalyst. FESEM images showed that α-Bi2O3-ZnO photocatalyst is composed of dumbbell like structures of ZnO with breadth ranging 4-5 µm and length ranging from 10 to 11 µm respectively. It was observed that α-Bi2O3 nanoparticles were attached on the ZnO surface and were in contact with each other. Low recombination rate of photo-induced electron-hole pairs, due to the migration of electrons and holes between the photocatalyst could be responsible for the 100% photocatalytic efficiency of α-Bi2O3-ZnO composite. In addition, photocatalyst was also observed to show the excellent antimicrobial activity with 1.5 cm zone of inhibition for 1 mg L-1 dose, against the human pathogenic bacteria (S. aureus).

Nanotechnology enabled the enhancement of antitrypanosomal activity of piperine against Trypanosoma evansi.

Nanoencapsulation is the promising approach to enhance the therapeutic potential of a drug. In the present investigation, piperine-loaded nanocapsules (NCs) was prepared and evaluated for antitrypanosomal activity against the parasite Trypanosoma evansi, a causative agent of trypanosomiasis. Piperine, a bioactive compound was selected as an alternative for drugs that have been used for the treatment of the disease from decades to overcome the toxic effects or drug resistance effect. Moreover, piperine has reported to possess therapeutic potential against other Trypanosoma spp. and has also been reported to cause reactive oxygen species (ROS) mediated effect in cancer cells that was the other reason for the selection. To date, piperine and its nanoformulations have not been evaluated for their growth inhibitory effect against T. evansi. Piperine-loaded NCs exhibited more significant antitrypanosomal effect at approximately three-times less IC50 value 5.04 µM as compared to piperine (IC50-14.45 µM). Moreover, increased production of reactive oxygen species observed in the case of piperine-loaded NCs as that of pure piperine in the axenic culture of T. evansi. Furthermore, different concentrations of piperine-loaded NCs showed less cytotoxicity on horse peripheral blood mononuclear cells as liken to pure piperine. In conclusion, our results demonstrated that piperine-loaded NCs induced more generation of ROS that contributed inhibitory effect on the growth of Trypanosoma evansi as compared to pure drug.

Synthesis, thermal and surface activity of cationic single chain metal hybrid surfactants and their interaction with microbes and proteins.

A series of water-soluble metal functionalized surfactants have been prepared using commercially available surfactant cetyl pyridinium chloride and transition metal salts. These complexes were characterized in the solid state by elemental analysis, FTIR, 1H NMR and thermogravimetric analysis. The interfacial surface activity and aggregation behaviour of the metallosurfactants were analysed through conductivity, surface tension and small angle neutron scattering measurements. Our results show that the presence of metal ions as co-ions along with counter ions favours micellization at a low critical micellization concentration (CMC). Small angle neutron scattering revealed that the metallomicelles are of a prolate ellipsoidal shape and exhibit strong counterion binding. This article further describes the interaction of the metallosurfactants with transport protein Bovine Serum Albumin (BSA) using different spectroscopic techniques. A spectroscopic study was used to study the binding, interaction and quenching mechanism of BSA with the metallosurfactants. Gel electrophoresis (SDS-PAGE) and circular dichroism (CD) investigated the structural and conformational changes produced in BSA due to the metallosurfactants. The results indicate that there is an alteration in the secondary structure of BSA due to the electrostatic interaction between positive head groups and metal co-ions of the metallosurfactants and negatively charged amino acids of BSA. As the concentration increases, the α-helicity of BSA decreases and all the three studied metallosurfactants gave comparable results. Finally, the in vitro cytotoxicity and antimicrobial activity of the metallosurfactants were evaluated against erythrocytes and microorganisms, which showed prominent effects related to the presence of a metal ion in metallomicelles of the hybrid surfactants.

Potential use of ZnO@activated carbon nanocomposites for the adsorptive removal of Cd2+ ions in aqueous solutions.

Nowadays, the pollution in water resources has become a major concern, both environmentally and in perspective of human health. The bioaccumulation of pollutants, especially heavy metal ions through the food chain, poses a hazardous risk to humans and other living organisms. Nanomaterials and their composites have been recognized for their potential to resolve such problems. Herein, ZnO nanoparticles were synthesized and characterized via different microscopic/spectroscopic techniques. ZnO nanoparticles (i.e., 20 to 50 nm) were obtained in high yield via a facile chemical approach. The ratio of ZnO nanoparticles and activated carbon was optimized to achieve enhanced electrostatic interactions for the effective adsorption of cadmium ions (Cd2+). The adsorptive performance of the nanocomposite was further assessed in relation to several key parameters (e.g., contact time, solution pH, and adsorbent/adsorbate dosage). The nanocomposites (1 mg/ml) offered amaximum adsorption capacity of 96.2 mg/g for Cd2+ ions as confirmed through adsorption isotherms for a best interpretation of the adsorption phenomenon. The favourable adsorption capacity of the synthesized ZnO/activated carbon (9:1) nanocomposites supported their use as an efficient sorbent material in practical performance metrics (e.g., partition coefficient of 0.54 mg g-1µM-1) for the adsorption of Cd2+ ions.

Metal organic frameworks MIL-100(Fe) as an efficient adsorptive material for phosphate management.

The excessive discharge of phosphate in water bodies is one of the primary factors causing eutrophication. Therefore, its removal is of significant research interest. The present study deals with the development and performance of highly effective phosphate-adsorbent. Here, we have synthesized MIL-100(Fe) metal-organic frameworks as a facile strategy to effectively remove phosphate from eutropic water samples. The adsorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), and wavelength dispersive X-ray fluorescence (WDXRF). The phosphate adsorption performance of MIL-100(Fe) was evaluated with the help of different batch experiments relating to the effect of adsorbent/adsorbate concentrations and the solution pH. The MOF offered a maximum adsorption capacity of 93.6 mg g-1 for phosphate from aqueous solutions with Langmuir isotherm model (R2 = 0.99). MIL-100(Fe) offered an absolute phosphate adsorption performance with a partition co-efficient of 15.98 mg g-1 µM-1 at pH 4 and room temperature conditions. Final experiments with real water samples were also performed to examine the effectiveness of MIL-100(Fe) for phosphate adsorption even in the presence of other ions. These findings support the potential utility of MIL-100(Fe) as nanoadsorbent in phosphate removal for water management.

Nano-Biosensing Platforms for Detection of Cow's Milk Allergens: An Overview.

Among prevalent food allergies, cow milk allergy (CMA) is most common and may persist throughout the life. The allergic individuals are exposed to a constant threat due to milk proteins' presence in uncounted food products like yogurt, cheese, and bakery items. The problem can be more severe due to cross-reactivity of the milk allergens in the food products due to homologous milk proteins of diverse species. This problem can be overcome by proper and reliable food labeling in order to ensure the life quality of allergic persons. Therefore, highly sensitive and accurate analytical techniques should be developed to detect the food allergens. Here, significant research advances in biosensors (specifically immunosensors and aptasensors) are reviewed for detection of the milk allergens. Different allergic proteins of cow milk are described here along with the analytical standard methods for their detection. Additionally, the commercial status of biosensors is also discussed in comparison to conventional techniques like enzyme-linked immunosorbent assay (ELISA). The development of novel biosensing mechanisms/kits for milk allergens detection is imperative from the perspective of enforcement of labeling regulations and directives keeping in view the sensitive individuals.

Point-of-Care Strategies for Detection of Waterborne Pathogens.

Waterborne diseases that originated due to pathogen microorganisms are emerging as a serious global health concern. Therefore, rapid, accurate, and specific detection of these microorganisms (i.e., bacteria, viruses, protozoa, and parasitic pathogens) in water resources has become a requirement of water quality assessment. Significant research has been conducted to develop rapid, efficient, scalable, and affordable sensing techniques to detect biological contaminants. State-of-the-art technology-assisted smart sensors have improved features (high sensitivity and very low detection limit) and can perform in a real-time manner. However, there is still a need to promote this area of research, keeping global aspects and demand in mind. Keeping this view, this article was designed carefully and critically to explore sensing technologies developed for the detection of biological contaminants. Advancements using paper-based assays, microfluidic platforms, and lateral flow devices are discussed in this report. The emerging recent trends, mainly point-of-care (POC) technologies, of water safety analysis are also discussed here, along with challenges and future prospective applications of these smart sensing technologies for water health diagnostics.

Biocompatibility and Targeting Efficiency of Encapsulated Quinapyramine Sulfate-Loaded Chitosan-Mannitol Nanoparticles in a Rabbit Model of Surra.

Quinapyramine sulfate (QS) produces trypanocidal effects against the parasite Trypanosoma evansi but is often poorly tolerated and causes serious reactions in animals. The encapsulation of QS in chitosan-mannitol to provide sustained release would improve both the therapeutic effect of QS and the quality of life of animals treated with this formulation. QS was encapsulated into a nanoformulation prepared from chitosan, tripolyphosphate, and mannitol nanomatrix (ChQS-NPs). ChQS-NPs were well ordered in shape, with nanoparticle size, as determined by transmission electron microscopy and atomic force microscopy. Our research revealed dose-dependent effects on biosafety and DNA damage in mammalian cells treated with ChQS-NPs. ChQS-NPs were absolutely risk-free at effective as well as many times higher doses against T. evansi ChQS-NPs were effective in rabbits, as they killed the parasites, relieving the animals from the clinical symptoms of the disease. The extent of this protection was similar to that observed with the conventional drug at higher dosages (5 mg QS/kg of body weight). ChQS-NPs are safe, nontoxic, and more effective than QS and offer a promising alternative to drug delivery against surra in animal models. ChQS-NPs may be useful for the treatment of surra due to reduced dosages and frequency of administration.

Cationic double chained metallosurfactants: synthesis, aggregation, cytotoxicity, antimicrobial activity and their impact on the structure of bovine serum albumin.

Bovine serum albumin (BSA) is one of the most copious and significant blood proteins with dynamic structure. The understanding of the structural functionality of BSA and its interaction with metal ions is desired for various biological functions. Herein, three different metallosurfactants containing different transition metals and the same hydrophobic tail were engaged to investigate the structural transition of BSA. The metallosurfactants have been prepared by a combination of metal ions (M = Fe, Co and Ni) with cetylpyridinium chloride surfactant via the ligand insertion method and were characterized by elemental, FTIR, 1H-NMR, and thermogravimetric analysis (TGA). The obtained results reveal that insertion of a metal ion perturbs the aggregation behavior of the surfactant. Incorporation of a metal-ion has been found to decrease the CMC value of the surfactant, which has been supported by conductivity, surface tension and small angle X-ray scattering (SAXS). These metallosurfactants were employed to study the interaction and binding mechanism of BSA under physiological conditions. SDS-PAGE analysis points out a weak effect of metallosurfactants on the primary structure of BSA, whereas CD spectra implied a significant change in secondary structure with the decreased α-helical content of BSA. Fluorescence spectroscopy indicates the effect of metallosurfactants on the tertiary structure of BSA, whereas absorption spectra demonstrated static quenching with a blue shift in the presence of metallosurfactants. Moreover, unfolding of BSA in the presence of metallosurfactants has also been confirmed by SAXS studies. The overall results indicate that insertion of the metal ion into the framework of the surfactant structure enhances its protein binding/folding/unfolding abilities, which would be helpful in clinical as well as in life sciences.

Carbon nanotubes: a novel material for multifaceted applications in human healthcare.

Remarkable advances have been achieved in modern material technology, especially in device fabrication, and these have facilitated the use of diverse materials in various applications. Carbon nanotubes (CNTs) are being successfully implemented in drug delivery, sensing, water purification, composite materials, and bone scaffolds. Thus, CNTs must meet a wide range of criteria such as surface modification, high aspect ratio, desired conductivity, high porosity and loading, non-toxicity, specificity, and selectivity, and compatibility for device fabrication. The main focus of this review is to explore the maximum applications of CNTs for human health, and we particularly focus on nanocarrier and biomedical applications. The scope of this review initially covers the basic aspects of CNTs and is also extended further to describe their synthesis strategies as well as various challenges encountered in their functionalization, dispersion, and toxicity. Our discussion also emphasizes future directions for these emerging fields of research.

Robust and direct electrochemical sensing of arsenic using zirconia nanocubes.

The presence of heavy metal ions in the environment and in food items can severely harm human health. Thus, simple, reliable, sensitive, quick, and accurate methods for their detection must be developed as a means to improve healthcare worldwide. To this end, a robust method was developed for the direct sensing of arsenic(iii) in control and real environmental samples (at neutral pH) by a gold electrode that was modified with zirconia nanocubes synthesized via a facile hydrothermal route. This sensing system was used to build a sensing profile for arsenic ions after characterization of their elemental, optical, chemical, and morphological behavior. Electrochemical sensing of arsenic was achieved by cyclic voltammetry (CV) and chronoamperometry with an ultra-sensitivity of 550 nA cm(-2) ppb(-1) and a detection limit of 5 ppb (linear range of 5-60 ppb with a response time below 2 s). Although this system experienced small interference from Cd ions, the results of the real sample analysis were comparable to those of other standard techniques. The proposed method is advantageous and can be used to assess the toxicity of water, food, and other environmental samples without requiring any toxic solutions and/or gasses in any of the analytical steps. Moreover, due to its low price, portability, and easy mass production, it can be adopted for use in screen-printed electrodes.

Hybrid surfactants decorated with copper ions: aggregation behavior, antimicrobial activity and anti-proliferative effect.

In the present study, the emphasis is laid on the self aggregation behavior of copper based inorganic-organic hybrids in aqueous media. The two complexes, cationic hexadecyl pyridinium trichloro cuprate (1 : 1), [Cp](+)[CuCl3](-), and bishexadecylpyridinium tetrachloro cuprate (2 : 1), [Cp2](2+)[CuCl4](2-), were synthesized using the ligand insertion method. The complexes were characterized using elemental analysis, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), nuclear magnetic resonance (NMR) and thermogravimetric analysis. The copper complexes were found to be thermally stable, and in the solid state, they possessed the perovskite arrangement with [Cp2](2+)[CuCl4](2-) exhibiting superior stability and crystallinity. The self aggregation behavior of the prepared complexes was analyzed in solution phase (in aqueous medium) using surface tension, conductivity, XRD and small angle neutron scattering (SANS). The results show that the presence of copper as a co-ion in both the stoichiometries results in lower critical micellization concentrations than their precursor. Micellization was thermodynamically spontaneous and micelles formed were ellipsoidal in shape and underwent a prolate ellipsoidal growth with an increase in the concentration of metallosurfactant, as estimated from the SANS. Furthermore, these metallosurfactants were investigated for biocompatibility (using hemolytic assay), antimicrobial activity (fungus and bacteria) and cytotoxicity using human cancerous cells. The hemolysis activity was found to depend on the aggregated state of the metallosurfactants, displaying the highest activity in the monomeric state, and the minimum for post micellar concentrations. The surfactants were found to enhance the antibacterial activity by twofold or more, with the addition of metal in both the stoichiometries. On the contrary, for anticancer and antifungal activities, barely any regular trend or generalization could be obtained. Nevertheless, the copper complexes exhibited high IC50 values for fR2 (healthy cells) signifying their higher safety in comparison to the cancerous cells.

Multifaceted approach for the fabrication of metallomicelles and metallic nanoparticles using solvophobic bisdodecylaminepalladium (II) chloride as precursor.

A one-pot synthesis of solvophobic bisdodecylaminepalladium(II) chloride (complex 1) was performed. Complex 1 was characterized using X-ray crystallography and other techniques, namely, mass spectrometry, Fourier transform infrared, NMR, elemental analysis, etc. A multifaceted approach was taken to explore the potential applications of complex 1. The micellization ability of complex 1 was estimated using conductivity method in n-alcohols. The metallomicelles are formed in alcohols, and the process is thermodynamically spontaneous in nature. Using complex 1 as precursor, palladium (Pd) nanoparticles were fabricated using two-phase redox method, where reduction is being performed in core of metallomicelles formed by complex 1 in dichloromethane (DCM). The micellization in DCM is confirmed by small-angle X-ray scattering (SAXS). The SAXS measurements reveal that the micellar of core 4-5 nm is being formed, which further controls the size of nanoparticle. This approach was advantageous in terms of size control, methodology, and yield. Pd nanoparticles were characterized using transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and UV-visible spectroscopy and were also screened for bovine serum albumin interactions. Complex 1 and Pd nanoparticles were found to possess antimicrobial property with broad spectrum and are active against bacteria and fungi. The cytotoxicity analyses were performed over healthy cells (Vero cell lines extracted from kidney of green monkey), and the results reveal IC50 value of 10 µg/mL for complex 1.