Millettia pinnata plant pod extract-mediated synthesis of Bi2O3 for degradation of water pollutants.

In this study, plant extract obtained from pods of Millettia pinnata plant species was employed for nanosynthesis of Bi2O3. The as-synthesized semiconductor metal oxide nanoparticles were analyzed using various characterization tools such as X-ray diffraction (XRD), Scanning electron microscope (SEM), ultra violet-visible (UV-Vis), Fourier transform infrared (FTIR), Zeta potential, Raman, and X-ray photoelectron spectroscopy (XPS). The characterization results designate the formation of α and ß forms of Bi2O3. FESEM images demonstrate rod and flake-like nanostructures ranging from 25 to 70 nm. The green synthesized nanomaterial was found efficient for reduction of 4-nitro phenol (4-NP) and 4-nitro aniline (4-NA). However, it showed better performance toward the reduction of 4-NA. Photocatalytic investigations demonstrated that the green synthesized nanophotocatalyst was capable in degrading Amido Black 10B (AB-10B) dye efficiently under visible light illumination. 98.83% degradation of AB-10B dye was achieved within 120 min of irradiation under optimum conditions of photocatalyst dose and dye concentration. Active species trapping experiments revealed prominent role of superoxide radicals (•O2-) while hydroxyl radicals (•OH) played considerable role in the AB-10B photocatalytic degradation process. Moreover, the photostability and reusability assessment study ascertained good performance of the catalyst after four runs of successive cycles.

Heat and let dye: Fixing blood-contaminated fingermarks using heat.

Blood-contaminated fingermarks are significant evidence for forensic investigators in high-profile cases providing a direct link between the suspect and the crime. Although these marks are often visible, blood enhancement techniques are operationally used to recover maximal ridge detail. The standard protein dye-staining procedure includes a chemical blood-fixing step, which requires an initial, prolonged drying period, for natural coagulation to occur. However, in special cases, when it is crucial to detect forensic traces quickly, there is a need to speed up the enhancement process. This study explored, both theoretically and empirically, the use of heat as an alternative method to the standard chemical fixing. Three consecutive experiments were conducted in which blood-contaminated fingerprints were deposited on different types of surfaces (car parts, glass, and flooring tiles), and heated for different periods, prior to development by amido black solution. The results showed that heat was successful in fixing blood, while the required temperature and heating durations, were inversely proportional. This observation was in correlation with theoretical heat-transfer data, calculated by the Lumped Heat Capacity model, also demonstrating the impact of the thermal time constant of each surface, on the conditions required for the full fixing of blood. The experimental findings led to a design of a portable, and tailor-made heating device, examined for the use in crime scenes, allowing to shorten the necessary fixing process from hours to minutes. For future crime-scene work, this novel approach may be utilized for a rapid blood-fixing, especially in cases when the scene cannot be preserved.

Back to Amido Black: Uncovering touch DNA in blood-contaminated fingermarks.

Blood-contaminated fingermarks (FMs) found in violent crime scenes may directly connect the suspect to the crime by linking the FM to the suspect and the DNA from the blood to the victim. However, marks that are incomparable are considered "dead-evidence" as the link to the suspect is lost. In this study, a novel approach was attempted to uncover the trace amount of touch DNA of the suspect in such marks. We examined the effect of two enhancement methods, ninhydrin (NIN) and amido black (AB), on DNA recovery from blood-contaminated FMs. A total of 108 fingerprints were deposited in three sets of depleted blood prints, blood-contaminated FMs, and latent FMs. All FMs were developed by either NIN or AB, or left undeveloped as reference followed by the quantification of the total DNA amount. This work shows that while AB had a detrimental effect on the quantity of blood-derived DNA specifically, reducing it by half, no similar effect was observed for touch DNA in latent FMs. This reduction led to the alteration of the major-to-minor DNA profile ratio to 70:30, thus enabling to obtain two distinct DNA profiles of the suspect from the touch DNA as well as the victim's profile from the blood. From an operational perspective, the use of AB in crime scenes may have an added value to retrieve the crucial DNA profile of the suspect, thus resurrecting a "dead-evidence."

Design of PAMAM grafted chitosan dendrimers biosorbent for removal of anionic dyes: Adsorption isotherms, kinetics and thermodynamics studies.

PAMAM grafted chitosan as biocompatible adsorbent was synthesized through Michael addition of methyl acrylate followed by amidation of ethylenediamine on the chitosan backbone. Then, the adsorption capacity of bioadsorbents were assessed by employing two anionic dyes. The adsorption experiments were carried out using a batch adsorption system. The influence of various operational variables such as different PAMAM generations, pH, adsorbent dosage, contact time, initial dye concentration and temperature on the maximum adsorption capacity (qm) were investigated. The adsorbent consists of second generation of PAMAM (CS-PAMAM G2) demonstrated high removal efficiency for both dyes. The maximum adsorption capacity of CS-PAMAM G2 for Congo Red at certain operational conditions was 559.3 mg/g; while the maximum adsorption capacity for Amido Black 10B at certain operational conditions was 489.8 mg/g; which revealed endothermic and exothermic nature of adsorption process for Congo Red and Amido Black 10B, respectively. These results were then well confirmed by thermodynamics studies. Also, kinetic studies showed that the dye adsorption process followed a pseudo-second-order kinetic model. Moreover, among various applied isotherms, the experimental data were well-fitted by Sips model. Consequently, CS-PAMAM G2 showed superior potential for the removal of dyes from aqueous phase.

Digitally processing an image of a shoe impression in blood.

Shoeprints are valuable crime scene exhibits because, given a reasonable-quality impression and a suspect shoe, the forensic investigator can correlate the impression with the shoe and pin down a suspect. In similarity to bloody fingerprints, a common practice with bloody shoeprints is that the crime scene investigator photographs the impressions at a 90° angle with a scale, develops them with amido Black, and then photographs again. In most cases, the post-development prints will feature better and more details that are usually sufficient to perform a comparison between the impression found at the crime scene and suspect's shoes. This study examined shoeprints in blood that had been collected in an apartment in northern Israel where two bodies were found. The floor tiles in the apartment had featured a colored design which in the post-development photographs of the shoeprints blended in with the blood on the floor. As a result, the shoeprint impression was partial and small details were masked. In the laboratory, we processed the pre-amido Black photograph in several steps designed to increase contrast. The result of this digital processing was a full shoeprint sufficiently clear to display randomly acquired characteristics of the sole and subsequently establish identification between the impression found at the crime scene and suspect's shoes. When chemical amplification is not sufficient, it is worth exploring other methods before proceeding with the comparison, as it is sometimes still possible to extract information from the same data using alternative methods in order to achieve a conclusive result.

The investigation of Amido black 10B adsorption-photocatalytic degradation using the synergistic effect of Cr-doped ZnO/CDs nanocomposite under solar light.

In this work, the modification of ZnO nanoparticles with green synthesized carbon dots and Cr yielded a nanocomposite named Cr-doped ZnO/CDs. Further, 0.48 g/L of this nanocomposite was able to remove (95 ± 1) % of 25 mg/L Amido black 10B (AB10B) from a solution, by adsorption process less than 5 min. The photocatalytic property of Cr-doped ZnO/CDs was able to improve the removal efficiency of AB10B to 99% during irradiation of sunlight within 15 min. The maximum adsorbent capacity of Cr-doped ZnO/CDs nanocomposite was 152.4 mg/g. Unmodified ZnO nanoparticles (0.48 g/L) were able to remove only 30% of the dye within 60 min of irradiation. Its modification showed coupling the absorption and photocatalytic process dramatically increased the dye removal efficiency. Adsorption isotherm investigation indicated that the experimental data were fitted satisfactorily by the Langmuir model. This method is an economical method because the Cr-doped ZnO/CDs synthesis was easy and inexpensive, the dye removal time was very short, and infinite sunlight is required to remove the dye with high efficiency. Graphical abstract.

Sorption of Acid Black 1 dye onto bentonite - equilibrium and kinetic studies.

The present study shows sorption capacity of bentonite from the Slovak Jelsový Potok deposit for the anionic dye (Acid Black 1) from aqueous solutions and uses it as an effective and economical adsorbent for the removal of anionic dye. The laboratory experiments were carried out in batch method at 3 different sorbent doses (20, 10 and 5 g L-1) and an initial concentration of dye ranging from 1 to 1,000 mg L-1. The adsorption equilibria data were fitted by Freundlich, Langmuir, Dubinin-Radushkevich and Temkin isotherms. The Langmuir equation provided the best description for the sorption, indicating that adsorption occurred on a mono-layered surface. The maximum sorption capacity of bentonite has been estimated as 31.29 mg g-1. Moreover, the results showed that non-linear method could be a better way to obtain the isotherm parameters. The pseudo-first- and pseudo-second-order equations have been applied for the determination of time effect on sorption/removal of dye from solution. The highest determination coefficient values were observed for the pseudo-second-order model, suggesting chemical character of the adsorption process. Acid Black 1 was probably bound through chemisorption by forming hydrogen bonds between the Si-OH and Al-OH groups in the bentonite and the -NH, -NH2 and -OH groups in the dye.

Immunoelectrophoresis: A Method with Many Faces.

Immunoelectrophoresis (IEP) was the first practical method that combined electrophoresis and immunoprecipitation for identifying and characterizing proteins within complex mixtures. Over the years, IEP has been extended to include a variety of techniques and, as a general name, has been applied to virtually any technique that involves electrophoresis and antigen-antibody precipitin reaction for proteins. Because of the diversity in technical details of different IEP versions, the method described here deals only with classic IEP. Although it requires some manual expertise, IEP is versatile, relatively easy to customize, and economical with no need for expensive instrumentation. Further, it can discern identity, partial identity, and nonidentity of the proteins. Any low-viscosity body fluid specimen or, possibly, culture fluid and tissue extract could be tested with IEP if proper antibodies are available. With these attributes, classic IEP remains a valuable tool for clinical diagnostic testing, purity checking of biochemical and pharmaceutical products, and research.

Amido Black 10B a widely used azo dye causes DNA damage in pro- and eukaryotic indicator cells.

Acid Black 10B (AB10B) is widely used for the production of textiles, leather and prints. It is a representative of azo dyes and it is well documented that some of these compounds are mutagenic per se, and that cleavage products (in particular aromatic amines) may cause damage of the genetic material and cancer. Since no toxicological data on AB10B have been published, we evaluated its mutagenic activity in Salmonella/microsome assays and studied its acute toxic and genotoxic properties in a human derived liver cell line (HepG2) which retained the activities of drug metabolizing enzymes. The compound did not cause cytotoxicity (MTT assay), but clear genotoxic effects were detected in pro- and eukaryotic indicator cells. Dose dependent induction of his+ revertants was seen in strain TA98 which detects frameshift mutations without metabolic activation; a more pronounced effect was seen in its derivative YG1024 which overexpresses N-acetyltransferase. Induction of single/double strand breaks by Comet assay was detected with concentrations > 0.125 mg/mL in liver derived cells; as well as increased rates for micronucleus (reflecting structural and numeric chromosomal aberrations) and nuclear buds which are a consequence of gene amplifications were seen with a higher dose (2.0 mg/mL) (p < 0.05; Tukey's test). The mutational pattern which was observed in the bacterial tests indicates that the cleavage product p-nitroaniline may cause the genotoxic effects of the dye. Our findings indicate that exposure of humans and the release of the compound into the environment may lead to adverse effects due to its DNA damaging activity.

Ten Minute Stain to Detect Proteins in Polyacrylamide Electrophoresis Gels with Direct Red 81 and Amido Black.

Proteins separated by SDS-polyacrylamide gel electrophoresis need to be stained with organic dyes to be visualized. Once stained the intensity of each stained protein band can be used to compare the differences in protein concentration and to measure the relative concentration of any protein band. The most popular standard protein staining is with Coomassie Blue R-250 which takes an hour to stain proteins to saturation and several hours to remove background staining. Direct Red 81 and Amido Black stain proteins within 2.5 min and staining is complete by 10 min. Here the rapid staining of proteins with Direct Red 81 and Amido Black in comparison to staining with Coomassie Blue R-250 is described.

Detection of Aspartic Proteinase Activities Using Gel Zymography.

Gel zymography is a two-stage process where the proteins from the test sample are first separated by electrophoresis followed by the detection of the activity of hydrolytic enzymes. Many zymography procedures use sodium dodecyl sulfate (SDS) polyacrylamide gels copolymerized with an appropriate substrate. The procedure described here uses native polyacrylamide gel electrophoresis (PAGE) in the absence of both SDS and substrate. In order to visualize aspartic proteinase activity, the gel is impregnated in bovine hemoglobin at pH 3.0 for 15 min after the electrophoresis procedure. Subsequently, the gel is incubated in a humid container in the absence of hemoglobin for 1 h at 37 °C. At the end, the gel is stained with amido black and destained. Clear areas against a dark background corresponding to aspartic proteinase activities can be detected.

Nanostructured ZnO-TiO2 thin film oxide as anode material in electrooxidation of organic pollutants. Application to the removal of dye Amido black 10B from water.

Electrochemical oxidative degradation of diazo dye Amido black 10B (AB10B) as model pollutant in water has been studied using nanostructured ZnO-TiO2 thin films deposited on graphite felt (GrF) substrate as anode. The influence of various operating parameters, namely the current intensity, the nature and concentration of catalyst, the nature of electrode materials (anode/cathode), and the adsorption of dye and ambient light were investigated. It was found that the oxidative degradation of AB10B followed pseudo first-order kinetics. The optimal operating conditions for the degradation of 0.12 mM (74 mg L-1) dye concentration and mineralization of its aqueous solution were determined as GrF-ZnO-TiO2 thin film anode, 100 mA current intensity, and 0.1 mM Fe2+ (catalyst) concentration. Under these operating conditions, discoloration of AB10B solution was reached at 60 min while 6 h treatment needed for a mineralization degree of 91 %. Therefore, this study confirmed that the electrochemical process is effective for the degradation of AB10B in water using nanostructured ZnO-TiO2 thin film anodes.

Simultaneous removal of Cr(VI) and Amido black 10B (AB10B) from aqueous solutions using quaternized chitosan coated bentonite.

In this study, simultaneous removal of Cr(VI) and Amido Black 10B (AB10B) using quaternized chitosan coated bentonite was investigated by a batch method. The factors affecting adsorption process such as pH, adsorbent dosage, contact time and initial concentration and the interaction of two components in binary solutions have been studied. The results showed that the antagonism effect existed between Cr(VI) and AB10B in binary systems. The equilibrium time for Cr(VI) adsorption was less than the one for AB10B adsorption. The maximum adsorption capacities of the modified bentonite, according to the Langmuir isotherm model were 847.5mg/g for AB10B and 66.6mg/g for Cr(VI) at 298K. The experimental results demonstrated that both Cr(VI) and AB10B were well described by the pseudo-second-order model. Thermodynamic study depicted that the adsorption of Cr(VI) and AB10B onto the modified bentonite was both spontaneous. The adsorption for Cr(VI) was exothermic while the one for AB10B was endoth- ermic in nature.

A comparison of visible wavelength reflectance hyperspectral imaging and Acid Black 1 for the detection and identification of blood stained fingerprints.

Bloodstains are often encountered at scenes of violent crime and have significant forensic value for criminal investigations. Blood is one of the most commonly encountered types of biological evidence and is the most commonly observed fingerprint contaminant. Presumptive tests are used to test blood stain and blood stained fingerprints are targeted with chemical enhancement methods, such as acid stains, including Acid Black 1, Acid Violet 17 or Acid Yellow 7. Although these techniques successfully visualise ridge detail, they are destructive, do not confirm the presence of blood and can have a negative impact on DNA sampling. A novel application of visible wavelength hyperspectral imaging (HSI) is used for the non-contact, non-destructive detection and identification of blood stained fingerprints on white tiles both before and after wet chemical enhancement using Acid Black 1. The identification was obtained in a non-contact and non-destructive manner, based on the unique visible absorption spectrum of haemoglobin between 400 and 500nm. Results from the exploration of the selectivity of the setup to detect blood against ten other non-blood protein contaminants are also presented. A direct comparison of the effectiveness of HSI with chemical enhancement using Acid Black 1 on white tiles is also shown.

Chemical enhancement of fingermark in blood on thermal paper.

Chemical enhancement methods for fingermark in blood deposited on the surface of a thermal paper substrate were examined. The blood-sensitive reagents compared were LCV (leuco crystal violet), Amido black and Hungarian red. Fingermark in blood on the surface of thermal paper can be fixed with 2% 5-sulfosalicylic acid solution. LCV was found as an inadequate blood staining reagent because of bubbling, diffusion, and blurring on the surface of thermal paper. Hungarian red was also an inadequate blood staining reagent because excess Hungarian red on the surface of thermal paper was not washed away in the de-staining procedure. Amido black was the best staining reagent among three staining reagents compared. The maximum dilution ratio visible to the naked eye after Amido black staining was 1 in 80 for the thermally sensitive surface and 1 in 20 for the thermally non-sensitive surface.

Measuring Protein Concentration on Nitrocellulose and After the Electrophoretic Transfer of Protein to Nitrocellulose.

Proteins bind to nitrocellulose membranes when applied directly or after electrophoretic transfer from polyacrylamide electrophoresis gels. Proteins can be stained for visualization with organic dyes Ponceau S, amido black, Coomassie Blue, and colloidal silver/gold and the intensity of the stain is directly proportional to the amount of protein present. Chemicals that interfere with dye/protein interactions in solution can be removed by washing the nitrocellulose after protein application. A method is described whereby protein-dye complexes attached to the nitrocellulose can be solubilized, dissolving the nitrocellulose and releasing dye into solution for detection by a spectrophotometer. The concentration of the dyes Ponceau S, amido black, and colloidal silver is proportional to the concentration of protein. Proteins transferred electrophoretically from SDS-PAGE, isoelectric focusing, or 2D gels to nitrocellulose can be stained with amido black, protein bands excised, and the bound dye detected in a spectrophotometer to quantify proteins in the individual protein bands.

Protein Stains to Detect Antigen on Membranes.

Western blotting (protein blotting/electroblotting) is the gold standard in the analysis of complex protein mixtures. Electroblotting drives protein molecules from a polyacrylamide (or less commonly, of an agarose) gel to the surface of a binding membrane, thereby facilitating an increased availability of the sites with affinity for both general and specific protein reagents. The analysis of these complex protein mixtures is achieved by the detection of specific protein bands on a membrane, which in turn is made possible by the visualization of protein bands either by chemical staining or by reaction with an antibody of a conjugated ligand. Chemical methods employ staining with organic dyes, metal chelates, autoradiography, fluorescent dyes, complexing with silver, or prelabeling with fluorophores. All of these methods have differing sensitivities and quantitative determinations vary significantly. This review will describe the various protein staining methods applied to membranes after western blotting. "Detection" precedes and is a prerequisite to obtaining qualitative and quantitative data on the proteins in a sample, as much as to comparing the protein composition of different samples. "Detection" is often synonymous to staining, i.e., the reversible or irreversible binding by the proteins of a colored organic or inorganic chemical.

Variability in antioxidant/detoxification enzymes of Labeo rohita exposed to an azo dye, acid black (AB).

The aim of the present study was to evaluate effect of a highly toxic azo dye, acid black (AB) (CI: 20470, 96 h LC50=10 mg/L) on the biochemical responses of Labeo rohita. Antioxidant/detoxification enzymes such as glutathione-S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), acetylcholinesterase (AChE), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), acid phosphatase (AcP), alkaline phosphatase (AKP), alanine transaminase (ALT) and aspartate transaminase (AST) were determined in liver, kidney, gill, muscle and brain of L. rohita after 96 h exposure to 6 mg/L (LC10), 8 mg/L (LC30) and 10 mg/L (LC50) of dye with an aim to find out the target tissue and biomarker enzyme for AB. The fish were then kept for a recovery period of 90 days, and activity of the selected enzymes was determined at the end of this period. Present dye altered the activities of all these enzymes in the selected tissues of the experimental fish in a dose-dependent manner. SOD was the maximally affected enzyme, and liver was the most affected tissue. The results indicate that AB is very toxic to L. rohita as there was a significant effect of even 6 mg/L dose of the dye and the toxicity prolonged for a long time because the fish was not able to recover from the stress even 90 days after the exposure. The study suggests that SOD can be used as a biomarker enzyme and liver is the target tissue for AB.

Porous chitosan doped with graphene oxide as highly effective adsorbent for methyl orange and amido black 10B.

In the current study, porous chitosan aerogels doped with small amount of graphene oxide (CSGO aerogels) with high porosity (97.96-98.78%), extraordinarily high water absorption (5848-8917%) and low density (0.021-0.035 g cm(-3)) were prepared and used as adsorbents for two azo dyes methyl orange (MO) and amido black 10B (AB10B). The adsorption behavior of these CSGO aerogels and some influence factors such as pH value, graphene oxide (GO) loading, concentration of pollutants, as well as adsorption kinetics were studied. Specifically, the adsorption capacity for MO is 686.89 mg g(-1), the highest comparing with other publication results, and it is 573.47 mg g(-1) for AB10B. Since they are biodegradable, non-toxic, efficient, low-cost and easy to prepare, we believe that these porous CSGO aerogels will be a promising candidate for dye removal.

Adsorption of an anionic azo dye by cross-linked chitosan/bentonite composite.

In this study, cross-linked chitosan (CCS)/bentonite (BT) composite was prepared by the intercalation of chitosan in bentonite and the cross-linking reaction between chitosan and glutaraldehyde. CCS/BT composite was characterized by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric analyses (TGA). Their adsorption characteristics were assessed by using an azo dye (Amido Black 10B) as a model adsorbate. The adsorption of Amido Black 10B onto the CCS/BT composite was found to be optimal at pH 2. The adsorption isotherm was well described by the Langmuir model and the maximum adsorption capacity was 323.6 mg/g at 293K and pH 2. Amido Black 10B adsorption kinetics followed a pseudo-second-order kinetic model. The calculated thermodynamic parameters showed that the adsorption of Amido Black 10B by CCS/BT composite was spontaneous and endothermic in nature.