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1.
Sci Rep ; 12(1): 12621, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-35871246

RESUMO

Nonprotein coding RNA (npcRNA) is a transcribed gene sequence that is not able to translate into protein, yet it executes a specific function in modulation and regulation mechanisms. As npcRNA is highly resistant to the mutation, the Sau-02 npcRNA gene and its probe oligonucleotide, which are specifically present in Staphylococcus aureus and in methicillin-resistant S. aureus only, used to develop a highly specific and sensitive colorimetric assay on unmodified gold nanoparticles (AuNPs). Hybridization between the npcRNA Sau-02 gene sequences was detected through noncrosslinking AuNP aggregation in salt solution in the presence of probe-target gene sequences. AuNPs of 10 and 15 nm in sizes with monovalent ion salt (NaCl) solution were optimized as the ideal tool for investigating the stability of AuNPs upon the addition of gene sequences. The state dispersed and aggregated forms of 10 nm AuNPs with the presented colorimetric assay were justified through field emission scanning electron microscopy and atomic force microscopy. The particle distribution of two different AuNP states was evaluated through particle distribution analysis. The lowest detection amount of S. aureus npcRNA from the colorimetric assay performed was 6 pg/µL, as the color of AuNPs turned blue with the presence of probe oligonucleotides and target gene sequences.


Assuntos
Nanopartículas Metálicas , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Sequência de Bases , Colorimetria , Ouro , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Oligonucleotídeos , RNA não Traduzido , Infecções Estafilocócicas/genética , Staphylococcus aureus/genética
2.
J Anal Methods Chem ; 2022: 9740784, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35592850

RESUMO

Carcinoembryonic antigen (CEA) is a glycoprotein, one of the common tumor biomarkers, found at low levels in body fluids. Generally, overexpression of CEA is found in various cancers, including ovarian, breast, lung, colorectal, gastric, and pancreatic cancers. Since CEA is an important tumor biomarker, the quantification of CEA is helpful for diagnosing cancer, monitoring tumor progression, and the follow-up treatment. This research develops a highly sensitive sandwich aptasensor for CEA identification on an interdigitated electrode sensor. Carbon-based material was used to attach a higher anti-CEA capture aptamer onto the sensor surface through a chemical linker, and then, CEA was quantified by the aptamer. Furthermore, CEA-spiked serum was tested by using the immobilized aptamer, which was found to not affect the target validation. The limit of detection for CEA in PBS and serum is calculated from a linear regression graph to be 0.5 ng/mL with R 2 values of 0.9593 and 0.9657, respectively, over a linear range from 0.5 to 500 ng/mL. This CEA quantification by the aptasensor can help diagnose various surgical tumors and monitor their progression.

3.
Dev Neurosci ; 43(1): 53-62, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33849012

RESUMO

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) dysregulation is widely related with various psychiatric and neurological disorders, including schizophrenia, depression, Rett syndrome, and addiction, and the available evidence suggests that BDNF is also highly correlated with Parkinson's and Alzheimer's diseases. METHODS: The BDNF target sequence was detected on a capture probe attached on aluminum microcomb electrodes on the silicon wafer surface. A capture-target-reporter sandwich-type assay was performed to enhance the detection of the BDNF target. RESULTS: The limit of detection was noticed to be 100 aM. Input of a reporter sequence at concentrations >10 aM improved the detection of the target sequence by enhancing changes in the generated currents. Control experiments with noncomplementary and single- and triple-mismatches of target and reporter sequences did not elicit changes in current levels, indicating the selective detection of the BDNF gene sequence. CONCLUSION: The above detection strategy will be useful for the detection and quantification of BDNF, thereby aiding in the provision of suitable treatments for BDNF-related disorders.


Assuntos
Alumínio , Fator Neurotrófico Derivado do Encéfalo , Fator Neurotrófico Derivado do Encéfalo/genética , Eletrodos , Genótipo , Polimorfismo Genético , Polimorfismo de Nucleotídeo Único , Silício
4.
Int J Nanomedicine ; 16: 2311-2322, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33776435

RESUMO

BACKGROUND: Alzheimer's disease (AD) is a neurodegenerative chronic disorder that causes dementia and problems in thinking, cognitive impairment and behavioral changes. Amyloid-beta (Aß) is a peptide involved in AD progression, and a high level of Aß is highly correlated with severe AD. Identifying and quantifying Aß levels helps in the early treatment of AD and reduces the factors associated with AD. MATERIALS AND METHODS: This research introduced a dual probe detection system involving aptamers and antibodies to identify Aß. Aptamers and antibodies were attached to the gold (Au) urchin and hybrid on the carbon nanohorn-modified surface. The nanohorn was immobilized on the sensor surface by using an amine linker, and then a Au urchin dual probe was immobilized. RESULTS: This dual probe-modified surface enhanced the current flow during Aß detection compared with the surface with antibody as the probe. This dual probe interacted with higher numbers of Aß peptides and reached the detection limit at 10 fM with R2=0.992. Furthermore, control experiments with nonimmune antibodies, complementary aptamer sequences and control proteins did not display the current responses, indicating the specific detection of Aß. CONCLUSION: Aß-spiked artificial cerebrospinal fluid showed a similar response to current changes, confirming the selective identification of Aß.


Assuntos
Doença de Alzheimer/diagnóstico , Ouro/química , Sondas Moleculares/química , Nanopartículas/química , Peptídeos beta-Amiloides/metabolismo , Eletrodos , Humanos , Limite de Detecção , Modelos Lineares , Nanopartículas/ultraestrutura , Fragmentos de Peptídeos , Multimerização Proteica , Reprodutibilidade dos Testes , Espectrometria por Raios X , Propriedades de Superfície
5.
J Immunol Methods ; 489: 112942, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33333060

RESUMO

Highly sensitive and easy detection method for Alzheimer's disease (AD) with a suitable biomarker is mandatory for preventing the factors resulting from AD. This research reports a modified ELISA with graphene for the detection of AD biomarker amyloid beta (Aß) oligomer. Gold nanoparticle (AuNP) conjugated aptamer was used as the capture probe and attached on ELISA-graphene oxide surface through the amine linker. Antibody was used as the detection molecule to reach the maximum detection of Aß oligomer. Suitable level of APTMS (2%), size of AuNP (30 nm) and aptamer concentration (2 µM) were optimized. This sandwich pattern of aptamer-Aß oligomer-antibody helps to reach the detection at 50 pM on the optimized ELISA surface and the control experiments in the absence of Aß oligomer or anti-Aß oligomer antibody did not show the significant optical detection at 492 nm, indicting the specific detection. Further, Aß oligomer spiked artificial cerebrospinal fluid did not interfere the detection of Aß oligomer, confirming the selective detection. This new and modified ELISA surface helps to reach the lower detection of Aß oligomer and diagnose AD.


Assuntos
Peptídeos beta-Amiloides/análise , Aptâmeros de Nucleotídeos/química , Ensaio de Imunoadsorção Enzimática , Ouro/química , Grafite/química , Nanopartículas Metálicas/química , Fragmentos de Peptídeos/análise , Humanos
6.
Int J Nanomedicine ; 15: 10171-10181, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33363373

RESUMO

BACKGROUND: In recent years, nanomaterials have justified their dissemination for biosensor application towards the sensitive and selective detections of clinical biomarkers at the lower levels. MXene is a two-dimensional layered transition metal, attractive for biosensing due to its chemical, physical and electrical properties along with the biocompatibility. MATERIALS AND METHODS: This work was focused on diagnosing osteosarcoma (OS), a common bone cancer, on MXene-modified multiple junction triangles by dielectrode sensing. Survivin protein gene is highly correlated with OS, identified on this sensing surface. Capture DNA was immobilized on MXene by using 3-glycidoxypropyltrimethoxysilane as an amine linker and duplexed by the target DNA sequence. RESULTS: The limitation and sensitivity of detection were found as 1 fM with the acceptable regression co-efficient value (y=1.0037⨰ + 0.525; R2=0.978) and the current enhancement was noted when increasing the target DNA concentrations. Moreover, the control sequences of single- and triple-mismatched and noncomplementary to the target DNA sequences failed to hybridize on the capture DNA, confirming the specificity. In addition, different batches were prepared with capture probe immobilized sensing surfaces and proved the efficient reproducibility. CONCLUSION: This microgap device with Mxene-modified multiple junction triangles dielectrode surface is beneficial to quantify the survivin gene at its lower level and diagnosing OS complication levels.


Assuntos
Biomarcadores Tumorais/metabolismo , Técnicas Biossensoriais/métodos , Neoplasias Ósseas/diagnóstico , Osteossarcoma/diagnóstico , Elementos de Transição/química , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , DNA de Neoplasias/metabolismo , Eletrodos , Humanos , Microeletrodos , Nanoestruturas/química , Osteossarcoma/patologia , Espectroscopia Fotoeletrônica , Reprodutibilidade dos Testes , Survivina/metabolismo
7.
ACS Omega ; 5(40): 25899-25905, 2020 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-33073115

RESUMO

The primary reasons for myocardial infarction (MI) are pericarditis, arrhythmia, and heart failure, causing predominant deaths worldwide. Patients need a potential diagnostic system and treatment before cardiomyocyte damage. Cardiac biomarkers are released from myocytes immediately after a heart attack. Troponin is an efficient biomarker released from dead cells within a few hours. Aptamers are artificial antibodies used effectively in the biosensor field for biomarker detection. Along with aptamers, the application of nanomaterials is also expected to enhance the detection limits of biosensors. In this investigation, selected aptamers against cardiac troponin I (cTnI) were conjugated with gold nanoparticles (GNPs) to diagnose MI and compared with an aptamer-only control group on an interdigitated electrode surface. Based on electroanalysis, cTnI was detected at concentrations as low as 1 fM, and the detection limit improved to 100 aM when the aptamer was conjugated with GNP. In addition, aptamer-GNP conjugates increased the current level at the tested concentrations of cTnI. Control experiments with noncomplementary aptamers and relevant proteins did not result in notable changes in the current, demonstrating the selective detection of cTnI.

8.
Biomed Microdevices ; 22(4): 67, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32940771

RESUMO

Nanoscale materials have been employed in the past 2 decades in applications such as biosensing, therapeutics and medical diagnostics due to their beneficial optoelectronic properties. In recent years, silver nanoparticles (AgNPs) have gained attention due to their higher plasmon excitation efficiency than gold nanoparticles, as proved by sharper and stronger plasmon resonance peaks. The current work is focused on utilizing self-assembled DNA-AgNPs on microdevices for the detection of gynecological cancers. Human papilloma virus (HPV) mostly spreads through sexual transmittance and can cause various gynecological cancers, including cervical, ovarian and endometrial cancers. In particular, oncogene E7 from the HPV strain 16 (HPV-16 E7) is responsible for causing these cancers. In this research, the target sequence of HPV-16 E7 was detected by an AgNP-conjugated capture probe on a dielectrode sensor. The detection limit was in the range between 10 and 100 aM (by 3σ estimation). The sensitivity of the AgNP-conjugated probe was 10 aM and similar to the sensitivity of gold nanoparticle conjugation sensors, and the mismatched control DNA failed to detect the target, proving selective HPV detection. Morphological assessments on the AgNPs and the sensing surfaces by high-resolution microscopy revealed the surface arrangement. This sensing platform can be expanded to develop sensors for the detection various clinically relevant targets.


Assuntos
DNA/química , Neoplasias dos Genitais Femininos/diagnóstico , Nanopartículas Metálicas/química , Microtecnologia/instrumentação , Prata/química , Eletrodos , Feminino , Humanos , Limite de Detecção
9.
3 Biotech ; 10(8): 364, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32832325

RESUMO

In this study, biological deoxygenation of graphene oxide (GO) using an Eclipta prostrata phytoextract was performed via the infusion method. The presence of oxide groups on the surface of graphene and removal of oxides groups by reduction were characterized through morphological and structural analyses. Field emission scanning electron microscopy images revealed that the synthesized GO and rGO were smooth and morphologically sound. Transmission electron microscopy images showed rGO developing lattice fringes with smooth edges and transparent sheets. Atomic force microscopy images showed an increase in the surface roughness of graphite oxide (14.29 nm) compared with that of graphite (1.784 nm) due to the presence of oxide groups after oxidation, and the restoration of surface roughness to 2.051 nm upon reduction. Energy dispersive X-ray analysis indicated a difference in the carbon/oxygen ratio between GO (1.90) and rGO (2.70). Fourier-transform infrared spectroscopy spectrum revealed peak stretches at 1029, 1388, 1578, and 1630 cm-1 for GO, and a decrease in the peak intensity after reduction that confirmed the removal of oxide groups. X-ray photoelectron microscopy also showed a decrease in the intensity of oxygen peak after reduction. In addition, thermogravimetric analysis suggested that rGO was less thermally stable than graphite, graphite oxide, and GO, with rGO decomposing after heating at temperatures ranging from room temperature to 600 °C.

10.
Curr Med Imaging ; 16(5): 534-544, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484087

RESUMO

Cardiovascular death is one of the leading causes worldwide; an accurate identification followed by diagnosing the cardiovascular disease increases the chance of a better recovery. Among different demonstrated strategies, imaging on cardiac infections yields a visible result and highly reliable compared to other analytical methods. Two-dimensional spot tracking imaging is the emerging new technology that has been used to study the function and structure of the heart and test the deformation and movement of the myocardium. Particularly, it helps to capture the images of each segment in different directions of myocardial strain values, such as valves of radial strain, longitudinal strain, and circumferential strain. In this overview, we discussed the imaging of infections in the heart by using the two-dimensional spot tracking.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Ecocardiografia/métodos , Interpretação de Imagem Assistida por Computador/métodos , Adulto , Idoso , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
11.
Nanoscale Res Lett ; 15(1): 105, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32394009

RESUMO

Abdominal aortic aneurysm (AAA) refers to the enlargement of the lower artery of the abdominal aorta, and identification of an early detection tool is urgently needed for diagnosis. In the current study, an interdigitated electrode (IDE) sensing surface was used to identify miRNA-335-5p, which reflects the formation of AAAs. The uniformity of the silica material was observed by 3D profilometry, and the chemically modified highly conductive surface improved the detection via the I-V mode. The targeted miRNA-335-5p was detected in a dose-dependent manner and based on linear regression and 3σ analyses, the sensitivity was determined to be 1 fM with a biotinylated probe. The high specificity was shown by discriminating the target sequence from noncomplementary and single- and triple-mismatched sequences. These outputs demonstrated the high-performance detection of miRNA-335-5p with good reproducibility for determination of the severity of AAA.

12.
Sci Rep ; 10(1): 3351, 2020 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-32099019

RESUMO

An incredible amount of joss fly ash is produced from the burning of Chinese holy joss paper; thus, an excellent method of recycling joss fly ash waste to extract aluminosilicate nanocomposites is explored. The present research aims to introduce a novel method to recycle joss fly ash through a simple and straightforward experimental procedure involving acidic and alkaline treatments. The synthesized aluminosilicate nanocomposite was characterized to justify its structural and physiochemical characteristics. A morphological analysis was performed with field-emission transmission electron microscopy, and scanning electron microscopy revealed the size of the aluminosilicate nanocomposite to be ~25 nm, while also confirming a uniformly spherical-shaped nanostructure. The elemental composition was measured by energy dispersive spectroscopy and revealed the Si to Al ratio to be 13.24 to 7.96, showing the high purity of the extracted nanocomposite. The roughness and particle distribution were analyzed using atomic force microscopy and a zeta analysis. X-ray diffraction patterns showed a synthesis of faceted and cubic aluminosilicate crystals in the nanocomposites. The presence of silica and aluminum was further proven by X-ray photoelectron spectroscopy, and the functional groups were recognized through Fourier transform infrared spectroscopy. The thermal capacity of the nanocomposite was examined by a thermogravimetric analysis. In addition, the research suggested the promising application of aluminosilicate nanocomposites as drug carriers. The above was justified by an enzyme-linked apta-sorbent assay, which claimed that the limit of the aptasensing aluminosilicate-conjugated ampicillin was two-fold higher than that in the absence of the nanocomposite. The drug delivery property was further justified through an antibacterial analysis against Escherichia coli (gram-negative) and Bacillus subtilis (gram-positive).


Assuntos
Silicatos de Alumínio/farmacologia , Cinza de Carvão/farmacologia , Sistemas de Liberação de Medicamentos , Nanocompostos/ultraestrutura , Silicatos de Alumínio/química , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Quitosana/química , Cinza de Carvão/química , Escherichia coli/efeitos dos fármacos , Incineração , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/química , Tamanho da Partícula , Prata/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
13.
Nanoscale Res Lett ; 15(1): 33, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32016709

RESUMO

Head and neck cancer is a heterogeneous disease, originating in the squamous cells lining the larynx (voice box), mouth, pharynx (throat), nasal cavity and salivary glands. Head and neck cancer diagnosis at the later stage is greatly influencing the survival rate of the patient. It makes a mandatory situation to identify this cancer at the earlier stages of development with a suitable biomarker. Squamous cell carcinoma antigen (SCC-Ag) is a circulating serum tumour biomarker, and the elevated level has been found in the head and neck cancer patients and highly correlated with the tumour volume. The present research was carried out to detect and quantify the level of SCC-Ag on titanium oxide (TiO2)-modified interdigitated electrode sensor (IDE) by SCC-Ag antibody. The detection of SCC-Ag was found at the level of 100 fM, while it was improved to 10 fM when the antibody was conjugated with gold nanostar, representing a 10-fold improvement. Interestingly, this enhancement in sensitivity is 1000-folds higher than other substrates. Moreover, the specificity analysis was carried out using two different control proteins and noticed that the antibody only recognised SCC-Ag, indicating the specific detection on IDE-TiO2 sensing surface.

14.
Int J Biol Macromol ; 151: 1133-1138, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31743722

RESUMO

Haemophilia is a blood clotting disorder known as 'Christmas disease' caused when the blood has defect with the clotting factor(s). Bleeding leads various issues, such as chronic pain, arthritis and a serious complication during the surgery. Identifying this disease is mandatory to take the necessary treatment and maintains the normal clotting. It has been proved that the level of factor IX (FIX) is lesser with haemophilia patient and the attempt here is focused to quantify FIX level by interdigitated electrode (IDE) sensor. Single-walled carbon nanotube (SWCNT) was utilized to modify IDE sensing surface. On this surface, dual probing was evaluated with aptamer and antibody to bring the possible advantages. The detection limit with antibody was found to be 1 pM, while aptamer shows 100 fM. Further, a fine-tuning was attempted with sandwich pattern of aptamer-FIX-antibody and antibody-FIX-aptamer and compared. Specific elevation of detection with 10 folds was noticed and displayed the detection at 100 f. in both sandwich patterns. In addition, FIX was detected in the diluted human serum by aptamer-FIX-antibody sandwich, it was found that FIX detected from the dilution factor 1:640. A novel demonstration is with higher discrimination against other clotting factors, XI and VII.


Assuntos
Anticorpos , Aptâmeros de Peptídeos , Técnicas Biossensoriais , Testes de Coagulação Sanguínea , Sondas Moleculares , Nanotubos de Carbono , Fatores de Coagulação Sanguínea , Humanos , Nanotubos de Carbono/química , Sensibilidade e Especificidade
15.
J Anal Methods Chem ; 2019: 5676159, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31827972

RESUMO

Gestational hypertension is one of the complicated disorders during pregnancy; it causes the significant risks, such as placental abruption, neonatal deaths, and maternal deaths. Hypertension is also responsible for the metabolic and cardiovascular issues to the mother after the years of pregnancy. Identifying and treating gestational hypertension during pregnancy by a suitable biomarker is mandatory for the healthy mother and foetus development. Cortisol has been found as a steroid hormone that is secreted by the adrenal gland and plays a pivotal role in gestational hypertension. A normal circulating level of cortisol is involved in the regulation of blood pressure, and it is necessary to monitor the changes in the level of cortisol during pregnancy. In this work, aptamer-based colorimetric assay is demonstrated as a model with gold nanorod to quantify the level of cortisol using the coordinated aggregation (at 500 mM of NaCl) and dispersion (with 10 µM of aptamer), evidenced by the scanning electron microscopy observation and UV-visible spectroscopy analysis. This colorimetric assay is an easier visual detection and reached the limit of detection of cortisol at 0.25 mg/mL. This method is reliable to identify the condition of gestational hypertension during the pregnancy period.

16.
J Anal Methods Chem ; 2019: 6526850, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31886023

RESUMO

Parkinson's disease (PD) is a progressive health issue and influences an increasingly larger number of people, especially at older ages, affecting the central nervous system (CNS). Alpha-synuclein is a biomarker closely correlated with the CNS and PD. The loss of neuronal cells in the substantia nigra leads to the aggregation of alpha-synuclein in the form of Lewy bodies, and Lewy neuritis is a neuropathological hallmark. The therapeutic approach of PD focuses on alpha-synuclein as an important substrate of PD pathology. So far, research has focused on antialpha-synuclein to minimize the burden of extracellular alpha-synuclein in the brain, and as a consequence, it ameliorates inflammation. Interdigitated electrode (IDE) biosensors are efficient tools for detecting various analytes and were chosen in this study to detect alpha-synuclein on amine-modified surfaces by using antiaptamer-alpha-synuclein as the probe. In addition, a gold nanoparticle-conjugated aptamer was used to enhance the detection limit. The limit of detection for the binding between alpha-synuclein and aptamer was found to be 10 pM. Control experiments were performed with two closely related proteins, amyloid-beta and tau, to reveal the specificity; the results show that the aptamer only recognized alpha-synuclein. The proposed strategy helps to identify the binding of aptamer and alpha-synuclein and provides a possible method to lower alpha-synuclein levels and inflammation in PD patients.

17.
Sci Rep ; 9(1): 17013, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745155

RESUMO

Lung cancer is one of the most serious threats to human where 85% of lethal death caused by non-small cell lung cancer (NSCLC) induced by epidermal growth factor receptor (EGFR) mutation. The present research focuses in the development of efficient and effortless EGFR mutant detection strategy through high-performance and sensitive genosensor. The current amplified through 250 µm sized fingers between 100 µm aluminium electrodes indicates the voltammetry signal generated by means of the mutant DNA sequence hybridization. To enhance the DNA immobilization and hybridization, ∼25 nm sized aluminosilicate nanocomposite synthesized from the disposed joss fly ash was deposited on the gaps between aluminium electrodes. The probe, mutant (complementary), and wild (single-base pair mismatch) targets were designed precisely from the genomic sequences denote the detection of EGFR mutation. Fourier-transform Infrared Spectroscopy analysis was performed at every step of surface functionalization evidences the relevant chemical bonding of biomolecules on the genosensor as duplex DNA with peak response at 1150 cm-1 to 1650 cm-1. Genosensor depicts a sensitive EGFR mutation as it is able to detect apparently at 100 aM mutant against 1 µM DNA probe. The insignificant voltammetry signal generated with wild type strand emphasizes the specificity of genosensor in the detection of single base pair mismatch. The inefficiency of genosensor in detecting EGFR mutation in the absence of aluminosilicate nanocomposite implies the insensitivity of genosensing DNA hybridization and accentuates the significance of aluminosilicate. Based on the slope of the calibration curve, the attained sensitivity of aluminosilicate modified genosensor was 3.02E-4 A M-1. The detection limit of genosensor computed based on 3σ calculation, relative to the change of current proportional to the logarithm of mutant concentration is at 100 aM.


Assuntos
Técnicas Biossensoriais/métodos , Carcinoma Pulmonar de Células não Pequenas/genética , Técnicas Eletroquímicas/métodos , Neoplasias Pulmonares/genética , Silicatos de Alumínio/química , Técnicas Biossensoriais/instrumentação , DNA/química , DNA/genética , Eletrodos , Receptores ErbB/genética , Humanos , Nanopartículas Metálicas/química , Nanocompostos/química , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Int J Nanomedicine ; 14: 8469-8481, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31695375

RESUMO

BACKGROUND: A pandemic influenza viral strain, influenza A/California/07/2009 (pdmH1N1), has been considered to be a potential issue that needs to be controlled to avoid the seasonal emergence of mutated strains. MATERIALS AND METHODS: In this study, aptamer-antibody complementation was implemented on a multiwalled carbon nanotube-gold conjugated sensing surface with a dielectrode to detect pandemic pdmH1N1. Preliminary biomolecular and dielectrode surface analyses were performed by molecular and microscopic methods. A stable anti-pdmH1N1 aptamer sequence interacted with hemagglutinin (HA) and was compared with the antibody interaction. Both aptamer and antibody attachments on the surface as the basic molecule attained the saturation at nanomolar levels. RESULTS: Aptamers were found to have higher affinity and electric response than antibodies against HA of pdmH1N1. Linear regression with aptamer-HA interaction displays sensitivity in the range of 10 fM, whereas antibody-HA interaction shows a 100-fold lower level (1 pM). When sandwich-based detection of aptamer-HA-antibody and antibody-HA-aptamer was performed, a higher response of current was observed in both cases. Moreover, the detection strategy with aptamer clearly discriminated the closely related HA of influenza B/Tokyo/53/99 and influenza A/Panama/2007/1999 (H3N2). CONCLUSION: The high performance of the abovementioned detection methods was supported by the apparent specificity and reproducibility by the demonstrated sensing system.


Assuntos
Anticorpos Antivirais/imunologia , Aptâmeros de Nucleotídeos/química , Ouro/química , Vírus da Influenza A Subtipo H1N1/imunologia , Nanotubos de Carbono/química , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/virologia , Pandemias , Suínos/virologia , Animais , Proteínas do Sistema Complemento/metabolismo , Eletrodos , Glicoproteínas de Hemaglutininação de Vírus da Influenza/metabolismo , Limite de Detecção , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Transdução Genética
19.
J Anal Methods Chem ; 2019: 5872347, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31662948

RESUMO

Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.

20.
J Anal Methods Chem ; 2019: 5426974, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31583159

RESUMO

Cancer is the uncontrollable abnormal division of cell growth, caused due to the varied reasons. Cancer can be expressed in any part of the body, and it is one of the death-causing diseases. Human reproductive organs are commonly damaged by cancer. In particular, the women reproductive system is affected by various cancers including ovarian, cervical, endometrial, vaginal, fallopian tube, and vulvar cancers. Identifying these cancers at earlier stages prevents the damage to the organs. Aptamer is the potential probe that can identify these cancers. Aptamer is an artificial antibody selected from the randomized library of molecules and has a high binding affinity to the target biomarker. Targeting cancers in the reproductive organs using aptamers showed an excellent efficiency of detection compared to other probes. Different aptamers have been generated against the gynaecological cancer biomarkers, which include HE4, CA125, VEGF, OCCA (for ovarian cancer), EGFR, FGFR1, K-ras (for endometrial cancer), HPV E-16, HPV E-7, HPV E-6, tyrosine, and kinase (for cervical cancer), which help to identify the cancers in woman reproductive organs. In this overview, the biomarkers for gynecologic cancers and the relevant diagnosing systems generated using the specific aptamers are discussed. Furthermore, the therapeutic applications of aptamer with gynaecological cancers are narrated.

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