scholarly journals Gold nanoparticles-assisted plasmonic enhancement for DNA detection on the graphene-based portable SPR sensor

2020 ◽  
Author(s):  
Briliant Adhi Prabowo ◽  
Agnes Purwidyantri ◽  
Bei Liu ◽  
Hsin-Chih Lai ◽  
Kou-Chen Liu
Keyword(s):  
Gold Nanoparticles ◽  
Dna Hybridization ◽  
Limit Of Detection ◽  
Dna Detection ◽  
Integrated Approach ◽  
Optical Simulation ◽  
Range Limit ◽  
Plasmonic Enhancement ◽  
Spr Sensor ◽  
The Impact

The impact of different gold nanoparticles (GNPs) structures on the plasmonic enhancement for DNA detection is investigated on a few-layer graphene (FLG) surface plasmon resonance (SPR) sensor. Two distinct structures of gold nanourchins (GNu) and gold nanorods (GNr) were used to bind the uniquely designed single-stranded probe DNA (ssDNA) of Mycobacterium tuberculosis complex (MTBC) DNA. The two types of GNPs-ssDNA mixture were adsorbed onto the FLGcoated SPR sensor through the π-π stacking force between the ssDNA and the graphene layer. In the presence of the complementary single-stranded DNA (cssDNA), the hybridization process took place and gradually removed the probes from the graphene surface. From SPR sensor preparation, the annealing process of the Au layer of the SPR sensor effectively enhanced the FLG coverage leading to a higher load of the probe DNA onto the sensing interface. The FLG was shown effective in providing a larger surface area for biomolecular capture due to its roughness. Carried out in the DNA hybridization study with SPR sensor, GNu, with its rough and spikey structures, significantly reinforced the overall DNA hybridization signal than the GNr with smooth superficies, especially in capturing the probe DNA. The DNA hybridization detection assisted by GNu reached the femtomolar range limit of detection (LoD). An optical simulation validated the extreme plasmonic field enhancement at the tip of the GNu spicules. The overall integrated approach of graphene-based SPR sensor and GNu-assisted DNA detection provided the proof-of-concept for the possibility for Tuberculosis disease screening using a low-cost and portable system potentially applied in remote or third world countries.

scholarly journals Application of Gold Nanoparticles for Electrochemical DNA Biosensor

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Ahmed Mishaal Mohammed ◽  
Ruslinda A. Rahim ◽  
Ibraheem Jaleel Ibraheem ◽  
Foo Kai Loong ◽  
Hasrul Hisham ◽  
...  
Keyword(s):  
Thin Films ◽  
Gold Nanoparticles ◽  
Dna Hybridization ◽  
Dna Detection ◽  
Dna Biosensor ◽  
Base Line ◽  
Frequency Range ◽  
Dna Immobilization ◽  
Electrochemical Dna Biosensor ◽  
Chemically Modified

An electrochemical DNA biosensor was successfully fabricated by using (3-aminopropyl)triethoxysilane (APTES) as a linker molecule combined with the gold nanoparticles (GNPs) on thermally oxidized SiO2thin films. The SiO2thin films surface was chemically modified with a mixture of APTES and GNPs for DNA detection in different time periods of 30 min, 1 hour, 2 hours, and 4 hours, respectively. The DNA immobilization and hybridization were conducted by measuring the differences of the capacitance value within the frequency range of 1 Hz to 1 MHz. The capacitance values for DNA immobilization were 160 μF, 77.8 μF, 70 μF, and 64.6 μF, respectively, with the period of time from 30 min to 4 hours. Meanwhile the capacitance values for DNA hybridization were 44 μF, 54 μF, 55 μF, and 61.5 μF, respectively. The capacitance value of bare SiO2thin film was 0.42 μF, which was set as a base line for a reference in DNA detection. The differences of the capacitance value between the DNA immobilization and hybridization revealed that the modified SiO2thin films using APTES and GNPs were successfully developed for DNA detection.

A carbon ink screen-printed immunoelectrode for Dengue virus NS1protein detection based on photosynthesized amine gold nanoparticles

2018 ◽  
pp. 1-12
Keyword(s):  
Gold Nanoparticles ◽  
Dengue Virus ◽  
Limit Of Detection ◽  
Colloidal Suspension ◽  
Electrochemical Immunosensor ◽  
Label Free ◽  
Vis Spectroscopy ◽  
Label Free Detection ◽  
The Impact ◽  
Screen Printed

Dengue virus (DENV) is a reemerging mosquito-borne disease that is endemic in more than 125 countries, affecting 200 million people per year. Screening testing has been a good attempt to minimize the impact caused by high morbity and mortality rates of DENV. In this study, a simple and disposable label-free electrochemical immunosensor based on a carbon ink graphite screen-printed electrode (SPE) one-step fabricated was developed for detection of non-structural 1 protein (NS1). The SPE surface was modified by drop casting, depositing a colloidal suspension containing amine-functionalized gold nanoparticles (AuNP-NH2). AuNPs were synthetized by a photoinduced physical method, illuminating preformed gold seeds with a light-emitting diode (LED,) at blue region, by using the polyethyleneimine (NH2) as reductor and stabilizing agent. UV-VIS spectroscopy and Transmission Electron Microscopy (TEM) were used to characterize the amine AuNPs. Electrocatalytic activity of AuNPs allowed more sensitivity for a label-free detection of NS1 by square wave voltammetry (SWV), with linear response from 0.1 to 2 µg mL-1. It was found a good linearity (coefficient of correlation of 0.995 (p<0.01) and a limit of detection of 0.03 µg mL-1 NS1 for analytical responses. AuNP-NH2 synthesis provided an easy oriented immobilization of anti-NS1 antibodies by Fc portion, resulting in a simple fabrication immunosensor with relative high performance and feasibility for early diagnostic of DENV.

scholarly journals In Situ Amplified Chemiluminescent Detection of DNA and Immunoassay of IgG Using Special-Shaped Gold Nanoparticles as Label

2006 ◽  
Vol 52 (10) ◽  
pp. 1958-1961 ◽  
Author(s):  
Zhouping Wang ◽  
Jianqiang Hu ◽  
Yan Jin ◽  
Xin Yao ◽  
Jinghong Li
Keyword(s):  
Gold Nanoparticles ◽  
Human Plasma ◽  
Clinical Laboratory ◽  
Limit Of Detection ◽  
Dna Detection ◽  
Clinical Samples ◽  
Plasma Samples ◽  
Au Nps ◽  
Human Plasma Samples

Abstract Background: Au(III) catalyzed luminol chemiluminescence (CL) is classic in luminescence analysis. Recently, spherical gold nanoparticles (Au-NPs) were found displaying far stronger catalytic activity on luminol CL than that of Au(III). Some methods based on Au-NPs probes have been developed for DNA detection or immunoassay. However, more complicated labeling or stripping procedures are often inescapable in these protocols. Methods: We synthesized specially shaped, irregular gold nanoparticles (IGNPs) and found their catalytic efficiency on luminol CL to be 100-fold greater than that of spherical Au-NPs. Using the IGNPs-functionalized DNA oligomers and the IGNPs-modified anti-IgG as in situ chemiluminescent probes, we established sandwich-type analytic methods for rapid, simple, selective, and sensitive sequence-specific DNA detection and for human plasma IgG immunoassay, respectively. We used 12 clinical human plasma samples to examine the precision and accuracy of the proposed method for IgG content determination. Results: Calibration curves for the oligonucleotide [ΔI = 15.73 + 27.55 (DNA) × 1010 (mol/L); R2 = 0.9936] and IgG [ΔI = 48.84 + 30.23 (IgG) × 1010 (mol/L); R2 = 0.9964] show good correlation, demonstrating the linear response over the concentrations tested (0.04–10 nmol/L for DNA, 0.05–10 nmol/L for IgG). The limit of detection, calculated based on 50 μL of a solution of calibrators, was 13 pmol/L for DNA and 17 pmol/L for IgG, with a signal-to-noise ratio of 3. We obtained good intra-and interassay reproducibility. The IgG contents in 12 human plasma samples obtained by the proposed method are identical with the data of clinical laboratory. Conclusions: We developed a simple and sensitive method for in situ amplified chemiluminescence detection of sequence-specific DNA and immunoassay of IgG by use of highly active, specially shaped, irregular gold nanoparticles (IGNPs) as label and confirmed by clinical samples test. This method has many desirable features including rapid detection, selectivity, and little required instrumentation. This new protocol may be quite promising, with potentially broad applications for clinical immunoassays and DNA hybridization analysis.

scholarly journals Oligonucleotide Detection and Optical Measurement with Graphene Oxide in the Presence of Bovine Serum Albumin Enabled by Use of Surfactants and Salts

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 420 ◽  
Author(s):  
Florentin R. Nitu ◽  
Jorge S. Burns ◽  
Mariana Ionită
Keyword(s):  
Graphene Oxide ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Dna Hybridization ◽  
Bovine Serum ◽  
Limit Of Detection ◽  
Dna Detection ◽  
Tween 20 ◽  
Specific Target ◽  
Target Probe

As graphene oxide-based oligonucleotide biosensors improve, there is a growing need to explore their ability to retain high sensitivity for low target concentrations in the context of biological fluids. Therefore, we innovatively combined assay milieu factors that could influence the key performance parameters of DNA hybridization and graphene oxide (GO) colloid dispersion, verifying their suitability to enhance oligonucleotide–GO interactions and biosensor performance. As a model system, we tested single-strand (ss) DNA detection in a complex solution containing bovine serum albumin (BSA) and salts with surfactants. A fluorescein conjugated 30-mer oligonucleotide ssDNA probe was combined with its complementary cDNA target, together with solute dispersed GO and either non-ionic (Triton X-100 and Tween-20) or anionic sodium dodecyl sulfate (SDS) surfactants. In this context, we compared the effect of divalent Mg2+ or monovalent Na+ salts on GO binding for the quench-based detection of specific target–probe DNA hybridization. GO biosensor strategies for quench-based DNA detection include a “turn on” enhancement of fluorescence upon target–probe interaction versus a “turn off” decreased fluorescence for the GO-bound probe. We found that the sensitive and specific detection of low concentrations of oligonucleotide target was best achieved using a strategy that involved target–probe DNA hybridization in the solution with a subsequent modified “turn-off” GO capture and the quenching of the unhybridized probe. Using carefully formulated assay procedures that prevented GO aggregation, the preferential binding and quenching of the unhybridized probe were both achieved using 0.1% BSA, 0.065% SDS and 6 mM NaCl. This resulted in the sensitive measurement of the specific target–probe complexes remaining in the solution. The fluorescein-conjugated single stranded probe (FAM–ssDNA) exhibited linearity to cDNA hybridization with concentrations in the range of 1–8 nM, with a limit of detection equivalent to 0.1 pmoles of target in 100 µL of assay mix. We highlight a general approach that may be adopted for oligonucleotide target detection within complex solutions.

The specifics of shadow economic activity in Russia

2020 ◽  
Vol 19 (10) ◽  
pp. 1896-1915
Author(s):  
E.R. Ermakova ◽  
O.M. Lizina
Keyword(s):  
Economic Activity ◽  
Shadow Economy ◽  
Integrated Approach ◽  
Economic Activities ◽  
Reproductive Process ◽  
Scientific Methods ◽  
Current Period ◽  
Russian Economy ◽  
Analysis And Synthesis ◽  
The Impact

Subject. The article addresses the specifics of shadow economic activities in reformed Russia in the context of systemic transformations. Objectives. We focus on determining the role of shadow economy in the reproductive process, identifying and understanding the specifics of underground economic activity of the Russian economy. Methods. The study rests on general scientific methods (scientific abstraction, unity of historical and logical, analysis and synthesis, induction and deduction, comparison and analogy) and special methods of cognition (monetary methods). We employ the systems and integrated approach. The official statistics, regulations, works of leading researchers on shadow economy expansion, resources of reference and legal systems like Garant and ConsultantPlus serve as the study's information base. Results. We present a retrospective rapid analysis of the extent of shadow economic activity in the domestic economy, establishing the relationships with the processes that take place at different stages of the country's development. We also reveal the specifics of shadow economy relations in Russia, factors that play a key role in expansion for a particular period, a shift to another form of shadow economy. The study characterizes the current period of development, assesses the impact of external shocks on shadow economy expansion. Conclusions. The current period is characterized by the digitization of shadow relations, the shift of corruption to the upper echelons of power, the continued outflow of capital abroad, and increased penalties for underground activities.

Assessing the sustainability of the Siberian Federal District regions

2020 ◽  
Vol 18 (5) ◽  
pp. 891-908
Author(s):  
T.A. Smirnova
Keyword(s):  
Sustainable Development ◽  
Environmental Factors ◽  
Regional Development ◽  
Federal District ◽  
Integrated Approach ◽  
Siberian Federal District ◽  
The Sustainable Development ◽  
The Impact ◽  
Empirical Analyses

Subject. This article deals with the issues of functioning of the region as a system. Objectives. The article aims to identify the problems of the region's functioning as a system, develop methodological tools to monitor the sustainable development of the Siberian Federal District territories, and determine the the impact of socio-economic and environmental factors on the sustainable development of the region as a whole. Methods. For the study, I used the methods of theoretical, statistical, and empirical analyses taking into account an integrated approach. Results. The article reveals the impact of some individual components of regional development on the sustainability of the territorial system as a whole. Relevance. The results of the study can be used to analyze the sustainability of regions' development.

Assessment of the influence of the spatial environment on the socio-economic development of the municipality

2019 ◽  
Vol 40 (3) ◽  
pp. 148-155
Author(s):  
K. N. Yusupov ◽  
V. M. Timiryanova, ◽  
Iu. S. Toktamysheva ◽  
A. F. Zimin,
Keyword(s):  
Economic Development ◽  
Socioeconomic Development ◽  
Statistical Data ◽  
Geographical Location ◽  
Integrated Approach ◽  
The State ◽  
Municipal District ◽  
Socio Economic Development ◽  
Spatial Environment ◽  
The Impact

The article presents a methodology for assessing the impact of spatial environment on the socioeconomic development of municipalities. It relies on existing tools for assessing the state and potential of the geographical location of municipalities. An integrated approach allows to determine the potential of the interaction of the municipality with the neighbors of the first and second order. The methodology was tested on statistical data on the Blagovarsky municipal district.

Indirect Determination of Amikacin by Gold Nanoparticles as Redox Probe

2020 ◽  
Vol 17 ◽  
Author(s):  
Mansureh Alizadeh ◽  
Mandana Amiri ◽  
Abolfazl Bezaatpour
Keyword(s):  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Cathodic Peak ◽  
Easy Method ◽  
Peak Current ◽  
Indirect Determination ◽  
Tract Infections

: Amikacin is an aminoglycoside antibiotic used for many gram-negative bacterial infections like infections in the urinary tract, infections in brain, lungs and abdomen. Electrochemical determination of amikacin is a challenge in electroanalysis because it shows no voltammetric peak at the surface of bare electrodes. In this approach, a very simple and easy method for indirect voltammetric determination of amikacin presented in real samples. Gold nanoparticles were electrodeposited at the surface of glassy carbon electrode in constant potential. The effect of several parameters such as time and potential of deposition, pH and scan rates on signal were studied. The cathodic peak current of Au3+ decreased with increasing amikacin concentration. Quantitative analysis of amikacin was performed using differential pulse voltammetry by following cathodic peak current of gold ions. Two dynamic linear ranges of 1.0 × 10−8–1.0 × 10-7 M and 5.0 × 10−7–1.0 × 10-3 M were obtained and limit of detection was estimated 3.0× 10−9 M. The method was successfully determined amikacin in pharmaceutical preparation and human serum. The effect of several interference in determination of amikacin was also studied.

scholarly journals Review on Sublethal Effects of Environmental Contaminants in Honey Bees (Apis mellifera), Knowledge Gaps and Future Perspectives

2021 ◽  
Vol 18 (4) ◽  
pp. 1863 ◽  
Author(s):  
Agata Di Noi ◽  
Silvia Casini ◽  
Tommaso Campani ◽  
Giampiero Cai ◽  
Ilaria Caliani
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Sublethal Effects ◽  
Integrated Approach ◽  
Anthropogenic Contamination ◽  
Knowledge Gaps ◽  
Pollination Services ◽  
General Decline ◽  
Polycyclic Aromatic ◽  
The Impact

Honey bees and the pollination services they provide are fundamental for agriculture and biodiversity. Agrochemical products and other classes of contaminants, such as trace elements and polycyclic aromatic hydrocarbons, contribute to the general decline of bees’ populations. For this reason, effects, and particularly sublethal effects of contaminants need to be investigated. We conducted a review of the existing literature regarding the type of effects evaluated in Apis mellifera, collecting information about regions, methodological approaches, the type of contaminants, and honey bees’ life stages. Europe and North America are the regions in which A. mellifera biological responses were mostly studied and the most investigated compounds are insecticides. A. mellifera was studied more in the laboratory than in field conditions. Through the observation of the different responses examined, we found that there were several knowledge gaps that should be addressed, particularly within enzymatic and molecular responses, such as those regarding the immune system and genotoxicity. The importance of developing an integrated approach that combines responses at different levels, from molecular to organism and population, needs to be highlighted in order to evaluate the impact of anthropogenic contamination on this pollinator species.

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