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1.
Forensic Sci Int ; 361: 112077, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38878615

RESUMO

Criminals often attempt to conceal blood-stained weapons used in violent crimes, making forensic evidence crucial in solving cases. This study explores the recovery and extraction of trace DNA from sports equipment, including cricket bats, table tennis racquets, and hockey sticks, which are frequently implicated in such incidents. Our research evaluates various double swab collection methods for retrieving trace DNA from these sports items, emphasizing those associated with blunt force trauma. We also compare presumptive and confirmatory tests to establish a direct correlation. This research consistently demonstrated robust DNA recovery, surpassing a 50 % threshold across all tests. Specifically, DNA recovery from buried samples reached an impressive 87 %, while washed samples still yielded a substantial 80 % efficiency. We conducted a comparative analysis between presumptive and confirmatory testing methods, establishing a direct correlation between the two. Variability in DNA recovery efficiency was observed and attributed to factors like the type of surface the items contacted, and ambient humidity levels. In addition to presenting robust DNA recovery rates, statistical analyses were employed to compare methods, establishing correlations and highlighting the influence of environmental factors on DNA recovery efficiency. These findings have significant implications for forensic investigations involving silent weapons crafted from sports equipment, emphasizing the need for standardized protocols and consideration of environmental factors in DNA analysis.

2.
Anal Chim Acta ; 1259: 341204, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37100479

RESUMO

Local air and water should be first priority to understand the environment of any area. Different categories of contaminants behave like bottleneck situation in collection and analysis of data about abiotic factors for the understanding and resolving the environmental issues. In digital age the emerging nano technology enroll its role to meet the needs of hour. Due to increase in pesticides residues, the global health threats are on bloom because it inhibits the functionality of acetylcholinesterase (AChE) enzyme. Smart nanotechnology based system can tackle this issue and sense the pesticides residues in environment and vegetables as well. Here Au@ZnWO4 composite is reported, for accurate detection of pesticides residues in biological food and environmental samples. The fabricated unique nanocomposite was characterized by SEM, FTIR, XRD and EDX. The characterized material used for the electrochemical detection of organophosphate pesticide (chlorpyrifos), with 1 pM LoD at a signal to noise ratio of 3. The main concern of study is to help out in disease prevention, food safety and ecosystem protection.


Assuntos
Inseticidas , Resíduos de Praguicidas , Praguicidas , Resíduos de Praguicidas/análise , Praguicidas/análise , Acetilcolinesterase/química , Ecossistema , Inseticidas/análise
3.
RSC Adv ; 9(12): 6793-6803, 2019 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35518460

RESUMO

Nanosensors with high sensitivity utilize electrical, optical, and acoustic properties to improve the detection limits of analytes. The unique and exceptional properties of nanomaterials (large surface area to volume ratio, composition, charge, reactive sites, physical structure and potential) are exploited for sensing purposes. High-sensitivity in analyte recognition is achieved by preprocessing of samples, signal amplification and by applying different transduction approaches. In this review, types of signals produced and amplified by nanosensors (based on transducers) are presented, to sense exceptionally small concentrations of analytes present in a sample. The use of such nanosensors, sensitivity and selectivity can offer different advantages in biomedical applications like earlier detection of disease, toxins or biological threats and create significant improvements in clinical as well as environmental and industrial outcomes. The emerging discipline of nanotechnology at the boundary of life sciences and chemistry offers a wide range of prospects within a number of fields like fabrication and characterization of nanomaterials, supramolecular chemistry, targeted drug supply and early detection of disease related biomarkers.

4.
J Hazard Mater ; 373: 50-59, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-30903956

RESUMO

Overuse and thus a constant presence of antibiotics leads to various environmental hazards and health risks. Thus, accurate sensors are required to determine their presence. In this work, we present a mass-sensitive sensor for the detection of rifampicin. We chose this molecule as it is an important antibiotic for tuberculosis, one of the leading causes of deaths worldwide. Herein, we have prepared a carbon nanotube reinforced with bismuth tungstate nanocomposite material in a well-defined nanosheet morphology using a facile in situ synthesis mechanism. Morphological characterization revealed the presence of bismuth tungstate in the form of square nanosheets embedded in the intricate network of carbon nanotubes, resulting in higher surface roughness of the nanocomposite. The synergy of the composite, so formed, manifested a high affinity for rifampicin as compared to the individual components of the composite. The developed sensor possessed a high sensitivity toward rifampicin with a detection limit of 0.16 µM and excellent specificity, as compared to rifabutin and rifapentine. Furthermore, the sensor yielded statistically good recoveries for the monitoring of rifampicin in human urine samples. This work opens up a new horizon for the exploration of unconventional nanomaterials bearing different morphologies for the detection of pharmaceuticals.


Assuntos
Antibacterianos/análise , Bismuto/química , Nanocompostos/química , Nanotubos de Carbono/química , Compostos de Tungstênio/química , Técnicas de Microbalança de Cristal de Quartzo
5.
J Hazard Mater ; 342: 96-106, 2018 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-28823921

RESUMO

Nanotechnology holds great promise for the fabrication of versatile materials that can be used as sensor platforms for the highly selective detection of analytes. In this research article we report a new nanohybrid material, where 3D imprinted nanostructures are constructed. First, copper nanoparticles are deposited on carbon nanotubes and then a hybrid structure is formed by coating molecularly imprinted polymer on 3D CNTs@Cu NPs; and a layer by layer assembly is achieved. SEM and AFM revealed the presence of Cu NPs (100-500nm) anchored along the whole length of CNTs, topped with imprinted layer. This material was applied to fabricate an electrochemical sensor to monitor a model veterinary drug, chloramphenicol. The high electron transfer ability and conductivity of the prepared material produced sensitive response, whereas, molecular imprinting produces selectivity towards drug detection. The sensor responses were found concentration dependent and the detection limit was calculated to be 10µM (S/N=3). Finally, we showed how changing the polymer composition, the extent of cross linking, and sensor layer thickness greatly affects the number of binding sites for the recognition of drug. This work paves the way to build variants of 3D imprinted materials for the detection of other kinds of biomolecules and antibiotics.


Assuntos
Antibacterianos/química , Cloranfenicol/química , Cobre/química , Nanotubos de Carbono/química , Polímeros/química , Antibacterianos/análise , Cloranfenicol/análise , Limite de Detecção , Impressão Molecular , Nanopartículas , Nanotecnologia
6.
Artif Cells Nanomed Biotechnol ; 46(sup1): 314-323, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29313367

RESUMO

We report a novel strategy for the fabrication of lecithin-coated gold nanoflowers (GNFs) via single-step design for CT imaging application. Field-emission electron microscope confirmed flowers like morphology of the as-synthesized nanostructures. Furthermore, these show absorption peak in near-infrared (NIR) region at λmax 690 nm Different concentrations of GNFs are tested as a contrast agent in CT scans at tube voltage 135 kV and tube current 350 mA. These results are compared with same amount of iodine at same CT scan parameters. The results of in vitro CT scan study show that GNFs have good contrast enhancement properties, whereas in vivo study of rabbits CT scan shows that GNFs enhance the CT image clearly at 135 kV as compared to that of iodine. Cytotoxicity was studied and blood profile show minor increase of white blood cells and haemoglobin, whereas decrease of red blood cells and platelets.


Assuntos
Meios de Contraste/química , Ouro/química , Lecitinas/química , Nanoestruturas/química , Tomografia Computadorizada por Raios X/métodos , Animais , Masculino , Coelhos
7.
J Virol Methods ; 249: 130-136, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28888402

RESUMO

The emergence of nanotechnology has opened new horizons for constructing efficient recognition interfaces. This is the first report where the potential of a multiwalled carbon nanotube based zinc nanocomposite (MWCNTs-Zn NPs) investigated for the detection of an agricultural pathogen i.e. Chili leaf curl betasatellite (ChLCB). Atomic force microscope analyses revealed the presence of multiwalled carbon nanotubes (MWCNTs) having a diameter of 50-100nm with zinc nanoparticles (Zn-NPs) of 25-500nm. In this system, these bunches of Zn-NPs anchored along the whole lengths of MWCNTs were used for the immobilization of probe DNA strands. The electrochemical performance of DNA biosensor was assessed in the absence and presence of the complementary DNA during cyclic and differential pulse voltammetry scans. Target binding events occurring on the interface surface patterned with single-stranded DNA was quantitatively translated into electrochemical signals due to hybridization process. In the presence of complementary target DNA, as the result of duplex formation, there was a decrease in the peak current from 1.89×10-04 to 5.84×10-05A. The specificity of this electrochemical DNA biosensor was found to be three times as compared to non-complementary DNA. This material structuring technique can be extended to design interfaces for the recognition of the other plant viruses and biomolecules.


Assuntos
Begomovirus/isolamento & purificação , Nanocompostos , Nanotecnologia/métodos , Vírus Satélites/isolamento & purificação , Zinco/química , Begomovirus/patogenicidade , Técnicas Biossensoriais , DNA/análise , Técnicas Eletroquímicas , Nanocompostos/química , Nanopartículas , Hibridização de Ácido Nucleico , Doenças das Plantas/virologia , Vírus Satélites/patogenicidade
8.
Biosens Bioelectron ; 89(Pt 2): 822-828, 2017 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-27816593

RESUMO

This work is the first report describing the development of a novel three dimensional manganese nanostructures based carbon nanotubes (CNTs-Mn NPs) composite, for the determination of ascorbic acid (vitamin C) in pharmaceutical formulation. Carbon nanotubes (CNTs) were used as a conductive skeleton to anchor highly electrolytic manganese nanoparticles (Mn NPs), which were prepared by a hydrothermal method. Scanning electron microscopy and atomic force microscopy revealed the presence of Mn Nps of 20-25nm, anchored along the whole length of CNTs, in the form of patches having a diameter of 50-500nm. Fourier transform infrared spectroscopy confirmed the surface modification of CNTs by amine groups, whereas dynamic light scattering established the presence of positive charge on the prepared nanocomposite. The binding events were studied by monitoring cyclic voltammetry signals and the developed nanosensor exhibited highly sensitive response, demonstrating improved electrochemical activity towards ascorbic acid. Linear dependence of the peak current on the square root of scan rates (R2=0.9785), demonstrated that the oxidation of ascorbic acid by the designed nanostructures is a diffusion control mechanism. Furthermore, linear range was found to be 0.06-4.0×10-3M, and nanosensor displayed an excellent detection limit of 0.1µM (S/N=3). This developed nanosensor was successfully applied for the determination of vitamin C in pharmaceutical formulation. Besides, the results of the present study indicate that such a sensing platform may offer a different pathway to utilize manganese nanoparticles based CNTs composite for the determination of other bio-molecules as well.


Assuntos
Ácido Ascórbico/análise , Técnicas Eletroquímicas/métodos , Manganês/química , Nanopartículas Metálicas/química , Nanotubos de Carbono/química , Vitaminas/análise , Eletrodos , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Nanotubos de Carbono/ultraestrutura
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