scholarly journals Pyrophosphate-Enhanced Oxidase Activity of Cerium Oxide Nanoparticles for Colorimetric Detection of Nucleic Acids

Sensors ◽  
2021 ◽  
Vol 21 (22) ◽  
pp. 7567
Author(s):  
Seokhwan Kim ◽  
Jinjoo Han ◽  
Heeseok Chung ◽  
Yong-Keun Choi ◽  
Ayemeh Bagheri Hashkavayi ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Cerium Oxide ◽  
Oxidase Activity ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Reaction Products ◽  
Biomolecular Detection ◽  
Bacterial Dna ◽  
Signal Change ◽  
Polymerase Chain

In recent years, cerium oxide (CeO2) nanoparticles (NPs) have drawn significant attention owing to their intrinsic enzyme mimetic properties, which make them powerful tools for biomolecular detection. In this work, we evaluated the effect of pyrophosphate (PPi) on the oxidase activity of CeO2 NPs. The presence of PPi was found to enhance the oxidase activity of CeO2 NPs, with enhanced colorimetric signals. This particular effect was then used for the colorimetric detection of target nucleic acids. Overall, the PPi-enhanced colorimetric signals of CeO2 NPs oxidase activity were suppressed by the presence of the target nucleic acids. Compared with previous studies using CeO2 NPs only, our proposed system significantly improved the signal change (ca. 200%), leading to more sensitive and reproducible colorimetric analysis of target nucleic acids. As a proof-of-concept study, the proposed system was successfully applied to the highly selective and sensitive detection of polymerase chain reaction products derived from Klebsiella pneumoniae. Our findings will benefit the rapid detection of nucleic acid biomarkers (e.g., pathogenic bacterial DNA or RNA) in point-of-care settings.

Ultrafast colorimetric detection of nucleic acids based on the inhibition of the oxidase activity of cerium oxide nanoparticles

2014 ◽  
Vol 50 (67) ◽  
pp. 9577-9580 ◽  
Author(s):  
Moon Il Kim ◽  
Ki Soo Park ◽  
Hyun Gyu Park
Keyword(s):  
Nucleic Acids ◽  
Cerium Oxide ◽  
Oxidase Activity ◽  
Colorimetric Detection ◽  
Colorimetric Method ◽  
Cerium Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Target Dna

A colorimetric method to detect nucleic acids involving target DNA induced shielding of the oxidase activity of CeO2 NPs is developed.

scholarly journals Nucleic Acids Analytical Methods for Viral Infection Diagnosis: State-of-the-Art and Future Perspectives

Biomolecules ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1585
Author(s):  
Emanuele Luigi Sciuto ◽  
Antonio Alessio Leonardi ◽  
Giovanna Calabrese ◽  
Giovanna De Luca ◽  
Maria Anna Coniglio ◽  
...  
Keyword(s):  
Nucleic Acids ◽  
Analytical Methods ◽  
Point Of Care ◽  
Low Cost ◽  
Genetic Material ◽  
Treatment And Prevention ◽  
Polymerase Chain ◽  
Silicon Based ◽  
User Friendly ◽  
Diagnosis Of Infection

The analysis of viral nucleic acids (NA), DNA or RNA, is a crucial issue in the diagnosis of infections and the treatment and prevention of related human diseases. Conventional nucleic acid tests (NATs) require multistep approaches starting from the purification of the pathogen genetic material in biological samples to the end of its detection, basically performed by the consolidated polymerase chain reaction (PCR), by the use of specialized instruments and dedicated laboratories. However, since the current NATs are too constraining and time and cost consuming, the research is evolving towards more integrated, decentralized, user-friendly, and low-cost methods. These will allow the implementation of massive diagnoses addressing the growing demand of fast and accurate viral analysis facing such global alerts as the pandemic of coronavirus disease of the recent period. Silicon-based technology and microfluidics, in this sense, brought an important step up, leading to the introduction of the genetic point-of-care (PoC) systems. This review goes through the evolution of the analytical methods for the viral NA diagnosis of infection diseases, highlighting both advantages and drawbacks of the innovative emerging technologies versus the conventional approaches.

scholarly journals Identification of Salmonella spp and serovars Typhimurium, Enteritidis by qPCR

2020 ◽  
pp. 21-31
Author(s):  
N. Rublenko
Keyword(s):  
Real Time ◽  
High Sensitivity ◽  
High Specificity ◽  
Analytical Sensitivity ◽  
Reaction Products ◽  
Salmonella Spp ◽  
Bacterial Dna ◽  
E Coli ◽  
Polymerase Chain ◽  
Primer Sets

This article presents the results of the identification of the Salmonella genus as well as serovars Enteritidis and Typhimurium by a real-time polymerase chain reaction. We constructed three pairs of primers and fluorescent probes to simultaneously identify the Salmonella genus, serovars Enteritidis and Typhimurium in a qPCR. The specificity of the primers was evaluated on Salmonella strains of different serovars from the National Center for Strains of Microorganisms (UNCMS) strains of the State Scientific Control Institute of Biotechnology and Strains of Microorganisms (SSCIBSM) and 46 Salmonella strains isolated from poultry. E. coli ATCC 25922, Bacillus cereus ATCC 11778, Listeria monocytogenes ATCC 19112 from UNCMS collection were used to check the specificity of the primers as heterologous samples. Bacterial DNA was extracted using a DNA Sorb B (Amplisens) kit, and realtime PCR was accomplished with the "Real-time PCR kit" (Syntol) on Bio-rad CFX. A series of 10-fold S. Typhimurium and S. Enteritidis DNA dilutions were studied to evaluate the sensitivity of the primers: 10-1-10-5. The analytical sensitivity of primers for detection of the genus Salmonella is: for S. Typhimurium - 0.25 ng/sample (Typhimurium) and S. Enteritidis - 0.27 ng/ sample (Enteritidis). The results of the studies confirmed the specificity of the primer set and the high sensitivity. No hybridization of primers with DNA samples of other bacteria found, in particular, the nonspecific reaction products were absent. The primer sets for the detection of DNA of Enteritidis and Typhimurium serovars also has high specificity. If necessary, this set of primers can be used to perform a multiplex qPCR, that can simultaneously identify bacteria of the Salmonella genus and differentiate Enteritidis and Typhimurium serovars. Keywords: Salmonella, bacteria, polymerasechainreaction, DNA, qPCR.

scholarly journals Nucleic acid amplification by a transparent graphene Visual-PCR chip and a disposable thermocycler

2019 ◽  
Author(s):  
Guozhi Zhu ◽  
Miao Qiao
Keyword(s):  
Nucleic Acids ◽  
Color Change ◽  
Point Of Care ◽  
Low Cost ◽  
Nucleic Acid Amplification ◽  
Driving Voltage ◽  
Conductive Films ◽  
Cooling Fan ◽  
Resource Limited ◽  
Polymerase Chain

ABSTRACTPolymerase chain reaction (PCR) is a method widely used to amplify trace amount of nucleic acids. It needs a process of thermocycling (repeated alternation of temperature). Traditional thermocycler relies on bulk size of metal block to achieve thermocycling, which results in high cost and the lack of portability. Here, a PCR chip made of graphene Transparent Conductive Films (TCFs) was employed. The thermocycling of the chip was fulfilled by a temperature programed microcontroller and a cooling fan under a low driving voltage (12V). A 35 cycles PCR was accomplished within 13 minutes using the chip and the thermocycler. The transparency of the graphene PCR chip enables the PCR reaction to be visually monitored by naked eye for a color change. The PCR chip and the thermocycler have a low cost at $2.5 and $6 respectively, and thus are feasible for Point-of-care testing (POCT) of nucleic acids in a disposable manner. The whole platform makes it possible to perform a low-cost testing of nucleic acids for varieties of purposes outside of laboratories or at resource limited locations.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM).The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

A Point of Care Lateral Flow Assay for Rapid and Colorimetric Detection of Interleukin 6 and Perspectives in Bedside Diagnostics

2020 ◽  
Author(s):  
Carla Eiras
Keyword(s):  
Interleukin 6 ◽  
Limit Of Detection ◽  
Inflammatory Diseases ◽  
Point Of Care ◽  
Colorimetric Detection ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Aggregation Assay ◽  
Before And After ◽  
Bedside Diagnosis

Interleukin-6 (IL-6) is a multifunctional cytokine and high bloodstream levels of which have been associated with severe inflammatory diseases, such as dengue fever, sepsis, various cancers, and visceral leishmaniasis (VL). Rapid tests for the quantification of IL-6 would be of great assistance for the bedside diagnosis and treatment of diseases such as VL. We have developed a lateral flow assay (LFA) for rapid and colorimetric IL-6 detection, consisting of anti-IL-6 antibodies conjugated to gold nanoparticles (AuNPs). The optimal concentration of anti-IL-6 used in the conjugate was determined to be 800.0 μg/mL, based on an aggregation assay using LFA. A linear relationship between IL-6 standard concentration and color intensity was observed after 20 min, with a linear range between 1.25 ng/mL and 9,000 ng/mL. The limit of detection for this method was estimated at a t0.38 ng/mL. The concentration of IL-6 in five patients with severe VL was measured using LFA, and the results were consistent with those obtained using the cytometric bead array (CBA) method. A thorough analysis of the LFA membranes’ surface morphology, before and after sample contact, was performed using atomic force microscopy (AFM). The prototype described here is still being tested and improved, but this LFA will undoubtedly be of great help in the clinical quantification of IL-6.

scholarly journals Screening, Diagnostic and Prognostic Tests for COVID-19: A Comprehensive Review

Life ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 561
Author(s):  
Mariana Ulinici ◽  
Serghei Covantev ◽  
James Wingfield-Digby ◽  
Apostolos Beloukas ◽  
Alexander G. Mathioudakis ◽  
...  
Keyword(s):  
Point Of Care ◽  
Standard Test ◽  
Current Evidence ◽  
Molecular Testing ◽  
Rt Pcr ◽  
Diagnostic Screening ◽  
Comprehensive Review ◽  
Prognostic Tests ◽  
Polymerase Chain ◽  
Antigen Testing

While molecular testing with real-time polymerase chain reaction (RT-PCR) remains the gold-standard test for COVID-19 diagnosis and screening, more rapid or affordable molecular and antigen testing options have been developed. More affordable, point-of-care antigen testing, despite being less sensitive compared to molecular assays, might be preferable for wider screening initiatives. Simple laboratory, imaging and clinical parameters could facilitate prognostication and triage. This comprehensive review summarises current evidence on the diagnostic, screening and prognostic tests for COVID-19.

scholarly journals LAMP-based foldable microdevice platform for the rapid detection of Magnaporthe oryzae and Sarocladium oryzae in rice seed

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. K. Prasannakumar ◽  
P. Buela Parivallal ◽  
Devanna Pramesh ◽  
H. B. Mahesh ◽  
Edwin Raj
Keyword(s):  
Magnaporthe Oryzae ◽  
Plant Pathogens ◽  
Point Of Care ◽  
Lamp Assay ◽  
Rice Seed ◽  
Highly Sensitive ◽  
Polymerase Chain ◽  
Rice Seeds ◽  
Template Dna ◽  
Assay Conditions

AbstractRice blast (caused by Magnaporthe oryzae) and sheath rot diseases (caused by Sarocladium oryzae) are the most predominant seed-borne pathogens of rice. The detection of both pathogens in rice seed is essential to avoid production losses. In the present study, a microdevice platform was designed, which works on the principles of loop-mediated isothermal amplification (LAMP) to detect M. oryzae and S. oryzae in rice seeds. Initially, a LAMP, polymerase chain reaction (PCR), quantitative PCR (qPCR), and helicase dependent amplification (HDA) assays were developed with primers, specifically targeting M. oryzae and S. oryzae genome. The LAMP assay was highly efficient and could detect the presence of M. oryzae and S. oryzae genome at a concentration down to 100 fg within 20 min at 60 °C. Further, the sensitivity of the LAMP, HDA, PCR, and qPCR assays were compared wherein; the LAMP assay was highly sensitive up to 100 fg of template DNA. Using the optimized LAMP assay conditions, a portable foldable microdevice platform was developed to detect M. oryzae and S. oryzae in rice seeds. The foldable microdevice assay was similar to that of conventional LAMP assay with respect to its sensitivity (up to 100 fg), rapidity (30 min), and specificity. This platform could serve as a prototype for developing on-field diagnostic kits to be used at the point of care centers for the rapid diagnosis of M. oryzae and S. oryzae in rice seeds. This is the first study to report a LAMP-based foldable microdevice platform to detect any plant pathogens.

scholarly journals INSIGHT: A population-scale COVID-19 testing strategy combining point-of-care diagnosis with centralized high-throughput sequencing

2021 ◽  
Vol 7 (7) ◽  
pp. eabe5054
Author(s):  
Qianxin Wu ◽  
Chenqu Suo ◽  
Tom Brown ◽  
Tengyao Wang ◽  
Sarah A. Teichmann ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Limit Of Detection ◽  
Point Of Care ◽  
Population Level ◽  
Reaction Products ◽  
Testing Strategy ◽  
Asymptomatic Patients ◽  
Testing Stage ◽  
Population Scale

We present INSIGHT [isothermal NASBA (nucleic acid sequence–based amplification) sequencing–based high-throughput test], a two-stage coronavirus disease 2019 testing strategy, using a barcoded isothermal NASBA reaction. It combines point-of-care diagnosis with next-generation sequencing, aiming to achieve population-scale testing. Stage 1 allows a quick decentralized readout for early isolation of presymptomatic or asymptomatic patients. It gives results within 1 to 2 hours, using either fluorescence detection or a lateral flow readout, while simultaneously incorporating sample-specific barcodes. The same reaction products from potentially hundreds of thousands of samples can then be pooled and used in a highly multiplexed sequencing–based assay in stage 2. This second stage confirms the near-patient testing results and facilitates centralized data collection. The 95% limit of detection is <50 copies of viral RNA per reaction. INSIGHT is suitable for further development into a rapid home-based, point-of-care assay and is potentially scalable to the population level.

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