scholarly journals Recent Advancements in Receptor Layer Engineering for Applications in SPR-Based Immunodiagnostics

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3781
Author(s):  
Marcin Drozd ◽  
Sylwia Karoń ◽  
Elżbieta Malinowska
Keyword(s):  
Medical Diagnostics ◽  
Label Free ◽  
Protein Receptors ◽  
Sensitivity And Selectivity ◽  
Analytical Reliability ◽  
Detection Of Biomarkers ◽  
Detection Strategies ◽  
Receptor Layer

The rapid progress in the development of surface plasmon resonance-based immunosensing platforms offers wide application possibilities in medical diagnostics as a label-free alternative to enzyme immunoassays. The early diagnosis of diseases or metabolic changes through the detection of biomarkers in body fluids requires methods characterized by a very good sensitivity and selectivity. In the case of the SPR technique, as well as other surface-sensitive detection strategies, the quality of the transducer-immunoreceptor interphase is crucial for maintaining the analytical reliability of an assay. In this work, an overview of general approaches to the design of functional SPR-immunoassays is presented. It covers both immunosensors, the design of which utilizes well-known and often commercially available substrates, as well as the latest solutions developed in-house. Various approaches employing chemical and passive binding, affinity-based antibody immobilization, and the introduction of nanomaterial-based surfaces are discussed. The essence of their influence on the improvement of the main analytical parameters of a given immunosensor is explained. Particular attention is paid to solutions compatible with the latest trends in the development of label-free immunosensors, such as platforms dedicated to real-time monitoring in a quasi-continuous mode, the use of in situ-generated receptor layers (elimination of the regeneration step), and biosensors using recombinant and labelled protein receptors.

scholarly journals Immunosensor Based on Long-Period Fiber Gratings for Detection of Viruses Causing Gastroenteritis

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 813 ◽  
Author(s):  
Marta Janczuk-Richter ◽  
Beata Gromadzka ◽  
Łukasz Richter ◽  
Mirosława Panasiuk ◽  
Karolina Zimmer ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Medical Diagnostics ◽  
Label Free ◽  
Fiber Gratings ◽  
Fast Detection ◽  
Long Period ◽  
Highly Sensitive ◽  
Protein Receptors ◽  
Long Period Fiber Gratings ◽  
Vaccine Testing

Since the norovirus is the main cause of acute gastroenteritis all over the world, its fast detection is crucial in medical diagnostics. In this work, a rapid, sensitive, and selective optical fiber biosensor for the detection of norovirus virus-like particles (VLPs) is reported. The sensor is based on highly sensitive long-period fiber gratings (LPFGs) coated with antibodies against the main coat protein of the norovirus. Several modification methods were verified to obtain reliable immobilization of protein receptors on the LPFG surface. We were able to detect 1 ng/mL norovirus VLPs in a 40-min assay in a label-free manner. Thanks to the application of an optical fiber as the sensor, there is a possibility to increase the user’s safety by separating the measurement point from the signal processing setup. Moreover, our sensor is small and light, and the proposed assay is straightforward. The designed LPFG-based biosensor could be applied in both fast norovirus detection and in vaccine testing.

Co-reactant Free Novel Self-enhanced Solid-state ECL Platform of Polyluminol-gold Nanocomposite for Highly Selective and Sensitive Signal-on Detection of Hg2+ ion

2020 ◽  
Author(s):  
Venkateswara Raju Chikkili ◽  
Senthil Kumar Shanmugam
Keyword(s):  
Solid State ◽  
Point Of Care ◽  
Deposition Process ◽  
Reduction Reaction ◽  
Label Free ◽  
Composite Surface ◽  
Site Monitoring ◽  
Sensitivity And Selectivity ◽  
One Step

Abstract Development of self-enhanced solid-state ECL platform creates a straightforward experimental design for the fabrication of point-of-care applications. Herein, we develop a promising method for self-enhanced solid-state ECL platform of polyluminol gold nanocomposite on glassy carbon electrode ((PL-Au)nano/GCE) via simple one step electrochemical deposition process without involving any additional co-reactants. The presence of AuNPs augments the electron transfer kinetics of PL and enhances the solid-state ECL intensity and promotes label free, excellent sensitivity, and selectivity to detect Hg2+ in physiological pH through signal-on mode. Unlike pristine PL/GCE, electrochemically co-deposited AuNPs in the (PL-Au)nano/GCE composite, enable the co-reactant accelerator by improving the catalytic activity of PL towards oxygen reduction reaction (ORR) yielding in-situ ROS (co-reactant) generation. Further, the ECL intensity of (PL-Au)nano/GCE composite, gradually increases by each addition of Hg2+ ion. This is because of the formation of an amalgamation of Au-Hg on (PL-Au)nano/GCE composite surface which further accelerate the yield of in-situ ROS and enhance the intensity of ECL. Whereas no ECL signals changes were observed for PL/GCE composite. The proposed self-enhanced solid-state ECL platform is selectively sensing the Hg2+ ion in the linear range of 0.3 nM to 200 nM with a detection limit of 0.1 nM. The demonstrated (PL-Au)nano/GCE platform might pave new avenues for further studies in the solid-state ECL platform which could be more useful in on-site monitoring of clinical bioassay and immunosensors.

scholarly journals Co-reactant-free self-enhanced solid-state electrochemiluminescence platform based on polyluminol-gold nanocomposite for signal-on detection of mercury ion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Chikkili Venkateswara Raju ◽  
Shanmugam Senthil Kumar
Keyword(s):  
Solid State ◽  
Point Of Care ◽  
Deposition Process ◽  
Reduction Reaction ◽  
Label Free ◽  
Composite Surface ◽  
Site Monitoring ◽  
Sensitivity And Selectivity ◽  
One Step

AbstractDevelopment of a self-enhanced solid-state ECL platform creates a straightforward experimental design for the fabrication of point-of-care applications. Herein, we develop a promising method for self-enhanced solid-state ECL platform of polyluminol gold nanocomposite on glassy carbon electrode [(PL-Au)nano/GCE] via simple one-step electrochemical deposition process without involving any additional co-reactants. The presence of gold nanoparticles (AuNPs) augments the electron transfer kinetics of PL (polyluminol) and enhances the solid-state ECL intensity and promotes label-free, excellent sensitivity, and selectivity to detect Hg2+ in physiological pH through signal-on mode. Unlike pristine PL/GCE, electrochemically co-deposited AuNPs in the (PL-Au)nano/GCE composite, enable the co-reactant accelerator by improving the catalytic activity of PL towards oxygen reduction reaction (ORR) yielding in-situ ROS (co-reactant) generation. Further, the ECL intensity of (PL-Au)nano/GCE composite, gradually increases with each addition of Hg2+ ion. This is because of the formation of an amalgamation of Au-Hg on (PL-Au)nano/GCE composite surface which further accelerates the yield of in-situ ROS and enhances the intensity of ECL. Whereas no ECL signals changes were observed for PL/GCE composite. The proposed self-enhanced solid-state ECL platform is selectively sensing the Hg2+ ion in the linear range of 0.3–200 nM with a detection limit of 0.1 nM. The demonstrated (PL-Au)nano/GCE platform might pave new avenues for further studies in the solid-state ECL platform which could be more useful in on-site monitoring of clinical bioassay and immunosensors.

scholarly journals Detection of Biomarkers Relating to Quality and Differentiation of Some Commercially Significant Whole Fish Using Spatially Off-Set Raman Spectroscopy

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3776
Author(s):  
Jeremy D. Landry ◽  
Peter J. Torley ◽  
Ewan W. Blanch
Keyword(s):  
Raman Spectroscopy ◽  
Food Production ◽  
Analytical Techniques ◽  
Label Free ◽  
Analysis Techniques ◽  
Chemical Analysis Techniques ◽  
Aquaculture Industry ◽  
Detection Of Biomarkers ◽  
Non Destructive

Aquaculture represents a major part of the world’s food supply. This area of food production is developing rapidly, and as such the tools and analytical techniques used to monitor and assess the quality of fish need to also develop and improve. The use of spatially off-set Raman spectroscopy (SORS) is particularly well-suited for these applications, given the ability of this technique to take subsurface measurements as well as being rapid, non-destructive and label-free compared to classical chemical analysis techniques. To explore this technique for analysing fish, SORS measurements were taken on commercially significant whole fish through the skin in different locations. The resulting spectra were of high quality with subsurface components such as lipids, carotenoids, proteins and guanine from iridophore cells clearly visible in the spectra. These spectral features were characterised and major bands identified. Chemometric analysis additionally showed that clear differences are present in spectra not only from different sections of a fish but also between different species. These results highlight the potential application for SORS analysis for rapid quality assessment and species identification in the aquaculture industry by taking through-skin measurements.

Pengaruh Jenis Co-Solvent terhadap Rendemen dan Mutu Biodiesel secara Transesterifikasi In Situ Menggunakan Radiasi Gelombang Mikro

2016 ◽  
Vol 10 (2) ◽  
pp. 119-126
Author(s):  
Mahlinda Mahlinda ◽  
Fitriana Djafar
Keyword(s):  
Catalyst Concentration ◽  
Maximum Yield ◽  
Acid Value ◽  
Experimental Result ◽  
In Situ Transesterification ◽  
Yield And Quality ◽  
Solvent Type ◽  
Biodiesel Quality

The main purpose of this research was to observer effect co-solvent type (n-Hexane, chloroform and without co-solvent)  toward yield and quality of biodiesel via in situ transesterification process using microwave irradiation. The process was studied at microwave power 450 watt, reaction time 4 minutes, methanol to seed ratio 25:1 and catalyst concentration 5%. The physicochemical parameters of the biodiesel produced such as viscosity, density and acid value were analysed and compared with the SNI 7182-2012 standard. The experimental result showed the maximum yield biodiesel 78,32% obtained by using co-solvent chloroform.Test result of physicochemical properties (viscosity, density and acid value) of biodiesel products using co solvent n-Hexane, chloroform and without co solvent showed that these products conform to the SNI 7182-2012 standars. The type of co-solvent only affectedon biodiesel yield dan not affected on biodiesel quality (viscosity, density and acid value).  ABSTRAKTujuan penelitian ini adalah untuk mempelajari pengaruh jenis co-solvent (n-Hexane, chloroform dan tanpa co-solvent) terhadap rendemen dan mutu biodiesel secara trasesterifikasi in situ menggunakan radiasi gelombang mikro. Proses dilakukan pada daya gelombang mikro 450 watt, waktu reaksi 4 menit, perbandingan berat metanol terhadap bahan baku 25:1 dan jumlah katalis 5%. Parameter fisiko kimia dari produk biodiesel seperti viskositas, densitas dan angka asam di analisa dan dibandingkan dengan standar SNI 7182-2012 tentang biodiesel. Hasil penelitian menunjukkan rendemen maksimum biodiesel sebesar 78,32% diperoleh dengan menggunakan co-solvent chloroform. Hasil pengujian  karakteristik fisiko kimia (viskositas, densitas dan angka asam) dari produk biodiesel menggunakan co-solvent n-Hexane, chloroform dan tanpa co-solvent menunjukkan bahwa semua parameter ini masih memenuhi standar SNI 1782-2012 tentang biodiesel. Jenis co-solvent hanya berpengaruh pada rendemen biodiesel dan tidak berpengaruh terhadap mutu biodiesel (viskositas, densitas dan bilangan asam).Kata kunci: co-solvent, in situ transesterifikasi, microwave, rendemen, mutu   

Estudio del proceso de lavado de contenedores para eliminar tiempos y movimientos innecesarios, caso: Wash Containers S.A de C.V.

2020 ◽  
pp. 25-36
Author(s):  
Juan Alfredo Lino-Gamiño ◽  
Carlos Méndez-González ◽  
Eduardo José Salazar-Araujo ◽  
Pablo Adrián Magaña-Sánchez
Keyword(s):  
Business Process ◽  
Value Chain ◽  
Process Management ◽  
Core Business ◽  
The Core ◽  
Washing Process ◽  
Overall Performance ◽  
The Times

In the value chain it is important to keep in mind the core business of the company, since it depends largely on the competitiveness of the company and its overall performance, bearing in mind that all business indicators depend on it. In this work we will study the washing process within the company WASH CONTAINERS SA DE CV, to improve the washing processes and in this way reduce times and movements in the process leading the company to reduce costs considerably within the operations company daily, having a more competitive operation and with greater profit margin in its business process. Goals: It Improve the logistics of the movement of containers for washing and with it the core business of the company. Methodology: The action research will be applied applying Business Process Management for the improvement of processes in situ, it will be developed in a certain period of time and with that it will establish an improvement projection. Contribution: The improvement of the times for the disposal of the containers and their subsequent use, allows a better competitiveness and with it the income of the company, on the other hand, the transport companies improve in performance in quantity, quality of disposition and with it their income.

scholarly journals Optical Monitoring of the Production Quality of Si-Nanoribbon Chips Intended for the Detection of ASD-Associated Oligonucleotides

Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 147
Author(s):  
Kristina A. Malsagova ◽  
Tatyana O. Pleshakova ◽  
Vladimir P. Popov ◽  
Igor N. Kupriyanov ◽  
Rafael A. Galiullin ◽  
...  
Keyword(s):  
Production Quality ◽  
Autism Spectrum ◽  
Covalent Immobilization ◽  
Biological Macromolecules ◽  
Label Free ◽  
Raman Scattering Spectroscopy ◽  
Dna Oligonucleotides ◽  
Highly Sensitive ◽  
Highly Sensitive Detection

Gas-phase etching and optical lithography were employed for the fabrication of a silicon nanoribbon chip (Si-NR chip). The quality of the so-fabricated silicon nanoribbons (Si-NRs) was monitored by optical Raman scattering spectroscopy. It was demonstrated that the structures of the Si-NRs were virtually defect-free, meaning they could be used for highly sensitive detection of biological macromolecules. The Si-NR chips were then used for the highly sensitive nanoelectronics detection of DNA oligonucleotides (oDNAs), which represent synthetic analogs of 106a-5p microRNA (miR-106a-5p), associated with the development of autism spectrum disorders in children. The specificity of the analysis was attained by the sensitization of the Si-NR chip sur-face by covalent immobilization of oDNA probes, whose nucleotide sequence was complementary to the known sequence of miR-106a-5p. The use of the Si-NR chip was demonstrated to al-low for the rapid label-free real-time detection of oDNA at ultra-low (~10−17 M) concentrations.

scholarly journals Modelling the Quality of Bathing Waters in the Adriatic Sea

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1525
Author(s):  
Christian Ferrarin ◽  
Pierluigi Penna ◽  
Antonella Penna ◽  
Vedrana Spada ◽  
Fabio Ricci ◽  
...  
Keyword(s):  
Adriatic Sea ◽  
Management Tool ◽  
Negative Consequences ◽  
Sea Temperature ◽  
Bathing Water Directive ◽  
Bathing Waters ◽  
Diffusion Dynamics ◽  
Study Sites

The aim of this study is to develop a relocatable modelling system able to describe the microbial contamination that affects the quality of coastal bathing waters. Pollution events are mainly triggered by urban sewer outflows during massive rainy events, with relevant negative consequences on the marine environment and tourism and related activities of coastal towns. A finite element hydrodynamic model was applied to five study areas in the Adriatic Sea, which differ for urban, oceanographic and morphological conditions. With the help of transport-diffusion and microbial decay modules, the distribution of Escherichia coli was investigated during significant events. The numerical investigation was supported by detailed in situ observational datasets. The model results were evaluated against water level, sea temperature, salinity and E. coli concentrations acquired in situ, demonstrating the capacity of the modelling suite in simulating the circulation in the coastal areas of the Adriatic Sea, as well as several main transport and diffusion dynamics, such as riverine and polluted waters dispersion. Moreover, the results of the simulations were used to perform a comparative analysis among the different study sites, demonstrating that dilution and mixing, mostly induced by the tidal action, had a stronger effect on bacteria reduction with respect to microbial decay. Stratification and estuarine dynamics also play an important role in governing microbial concentration. The modelling suite can be used as a beach management tool for improving protection of public health, as required by the EU Bathing Water Directive.

scholarly journals Chlorosulfuric acid-assisted production of functional 2D materials

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mohsen Moazzami Gudarzi ◽  
Maryana Asaad ◽  
Boyang Mao ◽  
Gergo Pinter ◽  
Jianqiang Guo ◽  
...  
Keyword(s):  
Hexagonal Boron Nitride ◽  
2D Materials ◽  
Real Life ◽  
Large Area ◽  
Polar Solvents ◽  
Aspect Ratios ◽  
Two Dimensional Materials ◽  
Liquid Phase Exfoliation

AbstractThe use of two-dimensional materials in bulk functional applications requires the ability to fabricate defect-free 2D sheets with large aspect ratios. Despite huge research efforts, current bulk exfoliation methods require a compromise between the quality of the final flakes and their lateral size, restricting the effectiveness of the product. In this work, we describe an intercalation-assisted exfoliation route, which allows the production of high-quality graphene, hexagonal boron nitride, and molybdenum disulfide 2D sheets with average aspect ratios 30 times larger than that obtained via conventional liquid-phase exfoliation. The combination of chlorosulfuric acid intercalation with in situ pyrene sulfonate functionalisation produces a suspension of thin large-area flakes, which are stable in various polar solvents. The described method is simple and requires no special laboratory conditions. We demonstrate that these suspensions can be used for fabrication of laminates and coatings with electrical properties suitable for a number of real-life applications.

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