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1.
Biosens Bioelectron ; 197: 113735, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34736114

RESUMO

In an aim of developing portable biosensor for SARS-CoV-2 pandemic, which facilitates the point-of-care aptasensing, a strategy using 10 µm gap-sized gold interdigitated electrode (AuIDE) is presented. The silane-modified AuIDE surface was deposited with ∼20 nm diamond and enhanced the detection of SARS-CoV-2 nucleocapsid protein (NCP). The characteristics of chemically modified diamond were evidenced by structural analyses, revealing the cubic crystalline nature at (220) and (111) planes as observed by XRD. XPS analysis denotes a strong interaction of carbon element, composed ∼95% as seen in EDS analysis. The C-C, CC, CO, CN functional groups were well-refuted from XPS spectra of carbon and oxygen elements in diamond. The interrelation between elements through FTIR analysis indicates major intrinsic bondings at 2687-2031 cm-1. The aptasensing was evaluated through electrochemical impedance spectroscopy measurements, using NCP spiked human serum. With a good selectivity the lower detection limit was evidenced as 0.389 fM, at a linear detection range from 1 fM to 100 pM. The stability, and reusability of the aptasensor were demonstrated, showing ∼30% and ∼33% loss of active state, respectively, after ∼11 days. The detection of NCP was evaluated by comparing anti-NCP aptamer and antibody as the bioprobes. The determination coefficients of R2 = 0.9759 and R2 = 0.9772 were obtained for aptamer- and antibody-based sensing, respectively. Moreover, the genuine interaction of NCP aptamer and protein was validated by enzyme linked apta-sorbent assay. The aptasensing strategy proposed with AuIDE/diamond enhanced sensing platform is highly recommended for early diagnosis of SARS-CoV-2 infection.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , COVID-19 , Doenças Transmissíveis , Nanodiamantes , Técnicas Eletroquímicas , Eletrodos , Ouro , Humanos , Limite de Detecção , Proteínas do Nucleocapsídeo , SARS-CoV-2
2.
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
3.
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
4.
Mikrochim Acta ; 186(8): 546, 2019 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-31321546

RESUMO

A genomic DNA-based colorimetric assay is described for the detection of the early growth factor receptor (EGFR) mutation, which is the protruding reason for non-small cell lung cancer. A DNA sequence was designed and immobilized on unmodified gold nanoparticles (GNPs). The formation of the respective duplex indicates the presence of an EGFR mutation. It is accompanied by the aggregation of the GNPs in the presence of monovalent ions, and it indicates the presence of an EGFR mutation. This is accompanied by a color change from red (520 nm) to purple (620 nm). Aggregation was evidenced by transmission electron microscopy, scanning electron microscopy and atomic force microscopy. The limit of detection is 313 nM of the mutant target strand. A similar peak shift was observed for 2.5 µM concentrations of wild type target. No significant peak shift was observed with probe and non-complementary DNA. Graphical abstract Schematic representation of high-specific genomic DNA sequence on gold nanoparticle (GNP) aggregation with sodium chloride (NaCl). It illustrates the detection method for EGFR mutation on lung cancer detection. Red and purple colors of tubes represent dispersed and aggregated GNP, respectively.


Assuntos
DNA de Cadeia Simples/química , Receptores ErbB/genética , Ouro/química , Nanopartículas Metálicas/química , Carcinoma Pulmonar de Células não Pequenas/genética , Colorimetria , Neoplasias Pulmonares/genética , Mutação
5.
Biosens Bioelectron ; 141: 111434, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31238281

RESUMO

The pragmatic outcome of a lung cancer diagnosis is closely interrelated in reducing the number of fatal death caused by the world's top cancerous disease. Regardless of the advancement made in understanding lung tumor, and its multimodal treatment, in general the percentage of survival remain low. Late diagnosis of a cancerous cell in patients is the major hurdle for the above circumstances. In the new era of a lung cancer diagnosis with low cost, portable and non-invasive clinical sampling, nanotechnology is at its inflection point where current researches focus on the implementation of biosensor conjugated nanomaterials for the generation of the ideal sensing. The present review encloses the superiority of nanomaterials from zero to three-dimensional nanostructures in its discrete and nanocomposites nanotopography on sensing lung cancer biomarkers. Recent researches conducted on definitive nanomaterials and nanocomposites at multiple dimension with distinctive physiochemical property were focused to subside the cases associated with lung cancer through the development of novel biosensors. The hurdles encountered in the recent research and future preference with prognostic clinical lung cancer diagnosis using multidimensional nanomaterials and its composites are presented.


Assuntos
Técnicas Biossensoriais/métodos , Neoplasias Pulmonares/diagnóstico , Nanoestruturas/química , Animais , Biomarcadores Tumorais/análise , Técnicas Biossensoriais/instrumentação , Humanos , Nanomedicina/instrumentação , Nanomedicina/métodos , Nanoestruturas/ultraestrutura , Nanotecnologia/instrumentação , Nanotecnologia/métodos
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