Gamma-irradiated Samples Research Articles

Effects of gamma and electron-beam irradiations on the stability of free radicals, bioactive compounds and microbial characteristics of turmeric powder

Turmeric is a functional ingredient commonly used in food, pharmaceutical, and cosmetic products due to its health benefits and bioactivity, including anti-inflammatory, antioxidant, and anticancer benefits. Irradiation is a common technique used to decontaminate microorganisms and extend the shelf life of spices. However, there are scientific debates over the use of irradiation in food products. This study aimed to assess the effects of ionizing radiation, including gamma rays and electron beams, on bioactive compounds and microbial characteristics of turmeric powder. Technically, high-performance liquid chromatography with UV-Vis detection was used to assess bioactive compounds. Another aim of the present study was to determine free radicals in irradiated and non-irradiated samples within one month of storage using electron paramagnetic resonance (EPR). Results showed that gamma and electron-beam irradiations could decrease microbial contamination of turmeric by approximately 5 and 6 log cfu/g, respectively. Contents of bioactive compounds increased in irradiated samples and curcumin contents in gamma and electron-beam irradiated samples were 232–248 and 215–266 mg/g dry weight (dw), respectively. Furthermore, the study detected that free radicals increased in all irradiated samples immediately after irradiation but decreased over time. Decrease in EPR signals was faster in gamma-irradiated samples during storage. Numbers of free radicals induced by gamma and electron-beam irradiations were 6.59–4.70, 2.69–1.60, 1.61–1.34, and 0.99–1.05 on days 0, 7, 14, and 21, respectively. After 21 days of storage, the numbers of free radicals in all non-irradiated and irradiated samples were similar. Therefore, free radicals induced by irradiations were degraded during storage and eliminated after 21 days.

Exogenous Brassinolide Ameliorates the Adverse Effects of Gamma Radiation Stress and Increases the Survival Rate of Rice Seedlings by Modulating Antioxidant Metabolism.

Gamma irradiation-based mutant creation is one of the most important methods for rice plant mutagenesis breeding and molecular biology research. Although median lethal dose irradiation severely damages rice seedlings, applying brassinolide (BR) can increase the survival rate of irradiated seedlings. In this study, we investigated the effects of soaking seeds in solutions containing different BR concentrations (0.001, 0.01, 0.1, 1.0, and 5.0 μmol/L) and then spraying the resulting seedlings twice with 0.1 μmol/L BR. The combined BR treatments markedly decreased the superoxide anion (O2•-), hydrogen peroxide (H2O2), and malondialdehyde contents but increased the chlorophyll content. An appropriate BR treatment of gamma-irradiated samples substantially increased the activities of the antioxidant enzymes superoxide dismutase, peroxidase, and ascorbate peroxidase as well as the proline, ascorbic acid, and glutathione contents in rice seedling shoots. The BR treatment also promoted the growth of seedlings derived from irradiated seeds and increased the shoot and root fresh and dry weights. Most notably, soaking seeds in 0.01 or 0.1 μmol/L BR solutions and then spraying seedlings twice with 0.1 μmol/L BR significantly increased the final seedling survival rate and decreased mutant loss. The study results suggest that exogenous BR treatments can protect rice seedlings from gamma irradiation stress by enhancing antioxidant metabolism.

Exploring the transformation: High-dosage gamma irradiation's role in tuning structural, optical, and electrical properties of cadmium-doped lead sulfide (PbS) nanoparticles

The effects of gamma irradiation on Cadmium-doped PbS (Cd-PbS) nanoparticles are thoroughly examined in this lattice study. The study sheds light on the changes in structural, morphological, and electrical properties brought about by Cd doping and gamma irradiation by employing a variety of methods such as X-ray diffraction, FESEM imaging, EDAX analysis, Raman spectroscopy, photoluminescence (PL) spectra, and Hall effect measurements. The Cd-doped PbS shows a fluctuating crystallite size as the average size first increases by ∼3 nm and then decreases by ∼3 nm with Cd concentration. This is due to the induced strain by the Cd dopant, which has a smaller ionic radius compared to Pb ions. With Cd substitution, the bandgap of PbS first decreases from 2.29 eV to 2.19 eV and then increases with mild fluctuations. Meanwhile, gamma irradiation causes these changes, decreasing the bandgap from 2.19 eV to 2.03 eV for lower Cd concentrations (x = 0.005) and increasing it to 2.41 eV for higher concentrations (x=0.01). The Hall data shows a wide range shift in electrical characteristics between the cadmium doped gamma-irradiated sample, and the pure sample, PS0. The electrical mobility increases from 6.05 V−1s−1 for PS0 to 4.95×102 V−1s−1 for GPS3 (higher cadmium concentration of x = 0.02), indicating a significant enhancement in which charge carriers can move through the material post-irradiation. Electrical resistivity shows a drastic increase from 4.42×101 Ωcm in PS0 to 9.41×102 Ωcm in GPS3, suggesting a marked increase in electrical conductivity post-irradiation. The findings demonstrate considerable changes in crystal characteristics, morphological transformations, increased crystallinity, and changed electrical properties, showing the promise of gamma-irradiated Cd-doped PbS in advanced optoelectronic device applications.

Investigate structural, morphological, electrical, dielectric and magnetic properties of dysprosium doped Cobalt-Nickel ferrites and their response to gamma irradiation

Nanocrystalline Co1-xNixFe2-yDy0.5O4 ferrites were successfully prepared by the sol–gel auto-combustion method. The samples were gamma-irradiated using a cobalt-60 source. XRD analysis reveals the formation of cubic spinel structure. FTIR study is used to confirm the formation of the expected spinel ferrite structure. Two probe method was used to measure DC electrical resistivity and the Arrhenius relation was used to calculate activation energy for non-irradiated and irradiated ferrites. Frequency dependent dielectric properties of the non-irradiated and irradiated ferrites were studied at room temperature. The dielectric constant for most of the gamma-irradiated samples increases because defects are induced in the material which increases space charge polarization in the samples. Magnetic properties of non-irradiated and irradiated nano ferrites were studied using VSM. Coercivity decreases after irradiation because decrease in grain size which increases surface state pinning of the domains.

Microstructural study of the Praid Salt Diapir (Transylvanian basin, Romania) and its implication on deformation history and hydrogen storage potential

The Transylvanian basin is one of the major Tertiary sedimentary basins in the Carpathian-Pannonian region. Its thick sedimentary fill contains prominent Middle Miocene age salt that forms major diapir structures at the basin margins. The microstructural characteristics of the rock salt represent one of the main factors that determines the potential of a salt body for storage of hydrogen. The main aim of this study is to extend our understanding of the deformation mechanism of Praid rock salt located at the eastern margin of the Transylvanian basin. Based on petrography, we identified two types of rock salt: (1) layered salt with rather uniform grain size distribution showing alternation of greyish (clay mineral bearing) and white (clear halite) layers, and (2) massive grey salt with large, elongated halite crystals, accompanied by sub-micrometer size grains of halite. To shed light on the microstructure of the rock salt, we performed electron backscatter diffraction (EBSD) mapping, and studied gamma-irradiated samples both in the massive and layered salt samples. Dislocation creep and pressure solution creep were identified which acted concurrently in the Praid rock salt. The total strain rate falls between 1.2 and 1.3×10−10 s−1. The results of this study reveal a complex deformation history of the salt body where coexisting and migrating fluids have played an important role. The outcome of this project contributes to the hydrogen storage potential assessment for the Transylvanian salt and to a better understanding of the structural evolution of the Transylvanian basin.

Estimating the initial absorbed dose of radiation in dried figs using EPR spectroscopy

Dried figs were studied by Electron Paramagnetic Resonance (EPR) spectroscopy for identification of radiation treatment and dosage assessment. Gamma-irradiated samples show a multicomponent "sugar-like" EPR spectrum with line width of 6–8 mT, centered at g = 2.004. The investigation of the influence of the instrumental parameters microwave power and modulation amplitude on the EPR signal show saturation effect at microwave power above 2 mW and over modulation at modulation amplitude above 0.4 mT. Determination of the stability of radiation induced signals shows, that identification of previous radiation treatment is possible for a long time period after irradiation even more than one year. Dose-response curves of gamma-irradiated samples exhibits a linear response up to about 4 kGy and the saturation of the EPR signal at higher doses. A Single Aliquot Additive dosing method used to estimate the initial absorbed dose in irradiated dried fig flesh shows initial dose 0.25 kGy for the sample irradiated by 5 kGy and 3.7 kGy for those irradiated using 10 kGy. Taking into account the signal decay after 150 days of storage, the dose defined as initial should be 4.65 kGy for the 5 kGy irradiated sample and 8 kGy for that irradiated using 10 kGy.

Effects of liquid-to-solid ratio and gamma irradiation on the rheology and cytocompatibility of a beta-tricalcium phosphate-based injectable bone substitute

Injectable bone substitute (IBS) materials are commonly used to fill irregular-shaped bone voids in non-load-bearing areas and can offer greater utility over those which are in prefabricated powder, granule, or block forms. This work investigates the impact of liquid-to-solid ratio (LSR) on the rheology and cytocompatibility of IBSs formulated from bioactive glass particles and β-tricalcium phosphate (β-TCP) in glycerol and poly(ethylene glycol) (PEG). IBS formulations of varying LSR were prepared and packed in 3 cc open-bore syringes and sterilized via gamma irradiation (10 kGy, 25 kGy). Gamma-irradiated formulations with high PEG content required the highest (73 N) mechanical force for injection from syringes. Oscillatory viscosity measurements revealed that the viscosity of samples was directly proportional to glycerol content. PEG and glycerol displayed competing effects on the washout resistance and cohesiveness of samples, which were based on total weight loss in media and Ca2+ ion release, respectively. Cell viability in 24-h extracts of 10 kGy gamma-sterilized and 25 kGy gamma-irradiated samples were 22.94% and 56.53%, respectively. The research highlights the complex interplay of IBS components on IBS rheology and, moreover, the cytotoxicity behaviors of beta-tricalcium phosphate-based injectable bone substitutes by in vitro experiments.

Enhanced exopolysaccharide production in gamma irradiated Bacillus subtilis: A biofilm-mediated strategy for ZnO nanoparticles removal

Biofilm-mediated strategy was studied for ZnO nanoparticle removal from aqueous media. Bacillus subtilis isolated from the soil rhizosphere was selected based on its high viscosity (133 Pa/s) of the cultivated culture and biofilm formation. The bacterium was exposed to gamma-irradiation to enhance EPS production along with its cultivation in EPS-producing media. The results show an increase in viscosity that reached 160 Pa/s at 2 kGy. EPS production increased from 4.45 to 7.95 mg/mL and the protein/carbohydrate ratio increased from 3 to 4.4 which reflects the stickiness of EPS. Thermal Gravimetric Analysis (TGA) showed 2 phase weight loss for gamma irradiated EPS and defined protein peaks when characterized using Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF). Native and gamma-irradiated Bacillus subtilis cells with their enhanced EPS were grown as a biofilm on sterile waste gauze fabric, Scanning Electron Microscopy (SEM) showed an increased biofilm attachment in gamma-irradiated samples. The latter was used for the removal of ZnO NP from aqueous media. Energy dispersive X-ray (EDX) mapping confirms that ZnO NPs were entrapped within the carbon and oxygen elements forming the biofilm with net intensities of 14.04, 1713, and 1190, respectively. The results confirm that biofilm-mediated strategy is effective in nanoparticles removal.

Radiation-induced lattice relaxation in alpha -Fe_2O_3 nanorods

We report radiation-induced lattice relaxation of the alpha -Fe_2O_3 and its associated alteration of particle morphology. The alpha -Fe_2O_3 was grown in solution by microwave hydrothermal synthesis technique in which more than half of the synthesized material was nanorods with axis along the (001) direction. Five sets of the synthesized alpha -Fe_2O_3 samples were irradiated using gamma-ray from ^{60}Co cell with doses of 600 kGy, 700 kGy, 800 kGy, 900 kGy, and 1 MGy. The investigation of the pristine and gamma-irradiated samples was carried out using X-ray powder diffraction, transmission electron microscope, and electron paramagnetic resonance methods. Results showed that continuous alternation of radiation-induced lattice compression and expansion causes lattice relaxation. The morphology of the alpha -Fe_2O_3 nanorods was found to change with absorbed dose into buckyball-shaped particles in response to the alternation of the compression and expansion strain. The EPR results showed a correlation between distortion in the O_h–FeO_6 octahedron structure and the relaxation of the lattice. The synthesis, growth, and relaxation are discussed in detail.

Potential antibacterial, antibiofilm, and photocatalytic performance of gamma-irradiated novel nanocomposite for enhanced disinfection applications with an investigated reaction mechanism

BackgroundWater scarcity is now a global challenge due to the population growth and the limited amount of available potable water. In addition, modern industrialization, and microbial pathogenesis is resulting in water pollution on a large scale.MethodsIn the present study, reusable Co0.5Ni0.5Fe2O4/SiO2/TiO2 composite matrix was incorporated with CdS NPs to develop an efficient photocatalyst, and antimicrobial agents for wastewater treatment, and disinfection purpose. The antibacterial performance of the gamma-irradiated samples was evaluated against various types of Gram-positive bacteria using ZOI, MIC, antibiofilm, and effect of UV-exposure. Antibacterial reaction mechanism was assessed by bacterial membrane leakage assay, and SEM imaging. In addition, their photocatalytic efficiency was tested against MB cationic dye as a typical water organic pollutant.ResultsOur results showed that, the formed CdS NPs were uniformly distributed onto the surface of the nanocomposite matrix. While, the resulted CdS-based nanocomposite possessed an average particle size of nearly 90.6 nm. The antibacterial performance of the prepared nanocomposite was significantly increased after activation with gamma and UV irradiations. The improved antibacterial performance was mainly due to the synergistic effect of both TiO2 and CdS NPs; whereas, the highest photocatalytic efficiency of MB removal was exhibited in alkaline media due to the electrostatic attraction between the cationic MB and the negatively-charged samples. In addition, the constructed heterojunction enabled better charge separation and increased the lifetime of the photogenerated charge carriers.ConclusionOur results can pave the way towards the development of efficient photocatalysts for wastewater treatment and promising antibacterial agents for disinfection applications.

Tuning dielectric response of polyethylene by low gamma dose: Molecular mobility study improvement by dipolar probes implementation

Dynamic Dielectric Spectroscopy is a powerful method to study the molecular mobility of dipolar polymers. As Linear Low Density Polyethylene is globally non polar, the dielectric experimental signal needs to be seriously improved. The aim of this study is to implement carbonyl groups by gamma irradiation, that act as dipolar probes in order to increase the signal to noise ratio. A specific attention is paid to induce as less modification as possible. Films were gamma irradiated in dioxygen media with different absorbed doses from 0 kGy to 100 kGy. After irradiation, better signal to noise ratios have been obtain thanks to polar probes introduction. The study of dielectric relaxation modes is then possible, extended and much more precise. One should irradiate the polymer with the lowest dose, between 12.5 kGy and 25 kGy, to obtain satisfactory Dynamic Dielectric Spectroscopy results with virtually no chemical and physical changes in the gamma irradiated samples.

Effect of gamma and Ultraviolet-C sterilization on BMP-7 level of indigenously prepared demineralized freeze-dried bone allograft.

The presence of bone morphogenetic proteins in demineralized freeze-dried bone allograft (DFDBA) are responsible for developing hard tissues in intraosseous defects. The most common mode of sterilization of bone allografts, i.e., Gamma rays, have dramatic effects on the structural and biological properties of DFDBA, leading to loss of BMPs. Ultraviolet-C radiation is a newer approach to sterilize biodegradable scaffolds, which is simple to use and ensures efficient sterilization.However, UV-C radiation has not yet been effectively studied to sterilize bone allografts. This study aimed to compare and evaluate the effectiveness of Gamma and Ultraviolet-C rays in sterilizing indigenously prepared DFDBA and assess their effect on the quantity of BMP-7 present in the allograft. DFDBA samples from non-irradiated, gamma irradiated, and UV-C irradiated groups were tested for BMP-7 level and samples sterilized with gamma and UV-C rays were analysed for sterility testing.The estimated mean BMP-7 level was highest in non-irradiated DFDBA samples, followed by UV-C irradiated, and the lowest in gamma irradiated samples. Our study concluded that UV-C rays effectively sterilized DFDBA as indicated by negative sterility test and comprised lesser degradation of BMP-7 than gamma irradiation.

Influence of gamma irradiation on the electrophysical properties of PVA/CdS polymer nanocomposites

PVA/CdS nanocomposites were obtained by forming cadmium sulfide (CdS) nanoparticles at 1, 3, 5 and 10 cycles in the pores of polyvinyl alcohol (PVA) by layered chemical sorption of anions and cations from a solution of the corresponding salts. A comparative analysis of the temperature-frequency dependence of the electrical properties of the original and gamma-irradiated samples was carried out. It is shown that the reason for the observed changes in the electrical properties of the initial PVA and PVA/CdS nanocomposites under the action of gamma radiation is a change in the ratio of crosslinking, degradation, and oxidation processes occurring in the matrix and at the polymer-filler interface with an increase in the absorbed dose.

Effects of Gamma Irradiation and Supercritical Carbon Dioxide Sterilization on Methacrylated Gelatin/Hyaluronan Hydrogels.

Biopolymer hydrogels have become an important group of biomaterials in experimental and clinical use. However, unlike metallic or mineral materials, they are quite sensitive to sterilization. The aim of this study was to compare the effects of gamma irradiation and supercritical carbon dioxide (scCO2) treatment on the physicochemical properties of different hyaluronan (HA)- and/or gelatin (GEL)-based hydrogels and the cellular response of human bone marrow-derived mesenchymal stem cells (hBMSC). Hydrogels were photo-polymerized from methacrylated HA, methacrylated GEL, or a mixture of GEL/HA. The composition and sterilization methods altered the dissolution behavior of the biopolymeric hydrogels. There were no significant differences in methacrylated GEL release but increased methacrylated HA degradation of gamma-irradiated samples. Pore size/form remained unchanged, while gamma irradiation decreased the elastic modulus from about 29 kPa to 19 kPa compared to aseptic samples. HBMSC proliferated and increased alkaline phosphatase activity (ALP) particularly in aseptic and gamma-irradiated methacrylated GEL/HA hydrogels alike, while scCO2 treatment had a negative effect on both proliferation and osteogenic differentiation. Thus, gamma-irradiated methacrylated GEL/HA hydrogels are a promising base for multi-component bone substitute materials.

Luminescence characteristics of white light emitting BaGa2O4:Dy3+ phosphors for LEDs and stress sensing applications

A series of single-phase white-light-emitting BaGa2O4:xDy3+(x = 0.1,0.3,0.5,0.7,1) phosphors have been synthesised using solid-state reaction technique. The structural studies using the X-ray diffraction (XRD) technique indicate that the phosphors are single-phase and Scanning Electron Microscope (SEM) study reveals that the particle size is in micrometer range. The phosphors emit white light with peaks at 346 nm, 357 nm, 386 nm, and 426 nm generated by Dy3+ ion transitions (6H15/2 → 6P7/2), (6H15/2 → 6P9/2), (6H15/2 → 4F7/2+4I13/2) and (6H15/2 → 4G11/2). The colour coordinates calculated for BaGa2O4:xDy3+ (x = 0.5,0.7) phosphors are identical to the conventional white light. BaGa2O4:Dy3+ exhibits good Mechanoluminescence (ML) response at varied impact velocities for both unirradiated and gamma-irradiated samples. This characteristic is reasonably beneficial in the development of damage and pressure sensors. Thermoluminescence (TL) analysis shows a single glow curve of similar shape irrespective of increasing irradiation, and the TL parameters have been calculated.

Electronic structure and defects induced luminescence study of phase stabilized t-ZrO2 nanocrystals.

Luminescent tetragonal-ZrO2 nanocrystals were synthesized using an optimized combustion method without post-synthesis annealing and characterized using X-ray diffraction, electron microscopy, Raman, X-ray photoelectron spectroscopy, UV-Visible, photoluminescence spectroscopy, thermoluminescence and vibrating sample magnetometry. The as synthesized t-ZrO2 nanocrystals have a band gap of 4.65 eV and exhibit defect assisted blue emission (CIE coordinates 0.2294,0.1984) when excited with 270 nm. The defect states were qualitatively and quantitatively analyzed using thermoluminescence (TL) after irradiating nanocrystals with gamma and UV radiation at various doses. The TL glow curves show intense emission in the high temperature region from 523-673 K for both UV and gamma irradiated samples; however, another less intense TL peak was also observed in the low temperature region from 333-453 K with gamma irradiation at higher doses, indicating the formation of shallow trapping states. The activation energies, frequency factor and order of kinetics were estimated through the computerized glow curve deconvolution method for the shallow and deep traps for γ and UV- irradiated samples. The present study shows that phase stabilized t-ZrO2 nanocrystals are potential candidates for luminescence-based applications.

Physico-Chemical Changes Induced by Gamma Irradiation on Some Structural Protein Extracts.

In this study, the effect of gamma irradiation (10 kGy) on proteins extracted from animal hide, scales, and wool was evidenced by calorimetric (μDSC) and spectroscopic (IR, circular dichroism, and EPR) methods. Keratin was obtained from sheep wool, collagen and bovine gelatin from bovine hide, and fish gelatin from fish scales. The μDSC experiments evidenced that gamma irradiation influences the thermal stability of these proteins differently. The thermal stability of keratin decreases, while a resistance to thermal denaturation was noticed for collagen and gelatins after gamma irradiation. The analysis of the IR spectra demonstrated that gamma irradiation determines changes in the vibrational modes of the amide groups that are associated with protein denaturation, most meaningfully in the case of keratin. As evidenced by circular dichroism for all proteins considered, exposure to gamma radiation produces changes in the secondary structure that are more significant than those produced by UV irradiation. Riboflavin has different effects on the secondary structure of the investigated proteins, a stabilizing effect for keratin and fish gelatin and a destabilizing effect for bovine gelatin, observed in both irradiated and non-irradiated samples. The EPR spectroscopy evidences the presence, in the gamma-irradiated samples, of free radicals centered on oxygen, and the increase in their EPR signals over time due to the presence of riboflavin.

A Study of Treatment of Reactive Red 45 Dye by Advanced Oxidation Processes and Toxicity Evaluation Using Bioassays

Advanced oxidation processes (AOPs) hold great promise to degrade and detoxify industrial-based effluents. The Reactive Red 45 dye aqueous solutions were treated with AOP using UV and gamma radiation alone and then in the presence of H2O2. The dye initial concentration, UV exposure time, and gamma-ray absorbed dose were optimized for maximum degradation. The degradation of dye was 88.85% and 77.7% using UV/H2O2 (1 mL/L) at a UV exposure time of 180 min for 50 mg/L and 100 mg/L, respectively. The degradation was noted as 100% and 93.82% as the solutions were subjected to a gamma/H2O2 (1 mL/L) absorbed dose of 2 kGy. The chemical oxygen demand was reduced to 77% and 85% by treating the dye samples with UV/H2O2 and gamma/H2O2, respectively. The removal efficiency (G-value), dose constant (k), D0.50, D0.90, and D0.99 for gamma-irradiated samples were also calculated. The reduction in toxicity for treated samples was monitored by using the Allium cepa, Hemolytic, and brine shrimp (Artemia salina) tests while the Ames test was performed for mutagenic assessment. The A. cepa test showed 39.13%, 36.36%, and 47.82% increases in root length (RL), root count (RC), and mitotic index (MI), respectively, in UV/H2O2-treated samples while 48.78%, 48.14%, and 57.14% increases were shown with gamma-ray in conjunction with H2O2. The hemolytic test showed 21.25% and 23.21% hemolysis after UV/H2O2 and gamma/H2O2 treatments, respectively. The brine shrimp (Artemia salina) test showed 84.09% and 90.90% decreases in the nauplii death after UV/H2O2 and gamma/H2O2 treatments, respectively. The mutagenicity of UV/H2O2-treated solutions was reduced up to 84.41% and 77.87%, while it was 87.83% and 80.88% using gamma/H2O2 using TA98 and TA100 bacterial strains, respectively. The advanced oxidation processes based on UV and gamma radiation in conjunction with H2O2 can be applied for the degradation and detoxification of textile waste effluents efficiently.

Theoretical analysis of thermal annealing kinetics of radiation defects in silica

The literature data on the annealing kinetics of the basic radiation defects in different types of silica after gamma- and neutron irradiation were analyzed in terms of diffusion-controlled reactions. The defect migration energies and relevant pre-factors are determined. It is shown that the annealing kinetics in several gamma and neutron irradiated samples could be explained as the recombination of the E′ centers (an oxygen vacancy) with two mobile hole defects, similarly to our recent observation in neutron irradiated sapphire. The mechanism of the relevant processes and a role of OH content are discussed.

Hierarchical Self-Assembly in DNA Ionogel: Effect of γ-Radiation on Gel Properties

DNA ionogels prepared by adding 1-ethyl-3-methylimidazolium chloride on low energy gamma irradiated DNA solution samples reveal non-trivial self-assembly. Variations in secondary structure and low-frequency gel rigidity modulus G0 captured this unique hitherto unexplored features of these gels. Interestingly, at higher radiation dose (0 to 100 Gy) samples could partially lose their initial rigidity. Dynamic light scattering revels dose dependent relaxation dynamics corresponding to ergodicity breaking time. In particular, viscosity and rheology showed that the time of gelation tgel, temperature of gelation Tgel and strength of gelation G0 are gamma ray dose dependent. DNA Ionogel melting with temperature shows self-assembled characteristics of this biomaterial. Gelation kinetics of ionizing radiation treated DNA strands have been studied in literature.