Electrochemical Biosensors Combined with Isothermal Amplification for Quantitative Detection of Nucleic Acids

The sensitive quantification of low-abundance nucleic acids holds importance for a range of clinical applications and biological studies. In this study, we describe a facile microfluidic chip for absolute DNA quantifications based on the digital loop-mediated isothermal amplification (digital LAMP) method. This microfluidic chip integrates a cross-flow channel for droplet generation with a micro-cavity for droplet tiling. DNA templates in the LAMP reagent were divided into ~20,000 water-in-oil droplets at the cross-flow channel. The droplets were then tiled in the micro-cavity for isothermal amplification and fluorescent detection. Different from the existing polydimethylsiloxane (PDMS) microfluidic chips, this study incorporates gold nanoparticles (AuNPs) into PDMS substrate through silica coating and dodecanol modification. The digital LAMP chip prepared by AuNPs-PDMS combines the benefits of the microstructure manufacturing performance of PDMS with the light-to-heat conversion advantages of AuNPs. Upon illumination with a near infrared (NIR) LED, the droplets were stably and efficiently heated by the AuNPs in PDMS. We further introduce an integrated device with a NIR heating unit and a fluorescent detection unit. The system could detect HBV (hepatitis B virus)-DNA at a concentration of 1 × 101 to 1 × 104 copies/μL. The LED-driven digital LAMP chip and the integrated device; therefore, demonstrate high accuracy and excellent performance for the absolute quantification of low-abundance nucleic acids, showing the advantages of integration, miniaturization, cost, and power consumption.

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Electrochemical Biosensors for Cytokine Profiling: Recent Advancements and Possibilities in the Near Future

Biosensors ◽

10.3390/bios11030094 ◽

2021 ◽

Vol 11 (3) ◽

pp. 94

Author(s):

Nirmita Dutta ◽

Peter B. Lillehoj ◽

Pedro Estrela ◽

Gorachand Dutta

Keyword(s):

Immune System ◽

Cost Effective ◽

Anomalous Behavior ◽

Quantitative Detection ◽

Electrochemical Biosensors ◽

Aberrant Expression ◽

Detection Techniques ◽

Short Period ◽

User Friendly ◽

Cytokine Profiling

Cytokines are soluble proteins secreted by immune cells that act as molecular messengers relaying instructions and mediating various functions performed by the cellular counterparts of the immune system, by means of a synchronized cascade of signaling pathways. Aberrant expression of cytokines can be indicative of anomalous behavior of the immunoregulatory system, as seen in various illnesses and conditions, such as cancer, autoimmunity, neurodegeneration and other physiological disorders. Cancer and autoimmune diseases are particularly adept at developing mechanisms to escape and modulate the immune system checkpoints, reflected by an altered cytokine profile. Cytokine profiling can provide valuable information for diagnosing such diseases and monitoring their progression, as well as assessing the efficacy of immunotherapeutic regiments. Toward this goal, there has been immense interest in the development of ultrasensitive quantitative detection techniques for cytokines, which involves technologies from various scientific disciplines, such as immunology, electrochemistry, photometry, nanotechnology and electronics. This review focusses on one aspect of this collective effort: electrochemical biosensors. Among the various types of biosensors available, electrochemical biosensors are one of the most reliable, user-friendly, easy to manufacture, cost-effective and versatile technologies that can yield results within a short period of time, making it extremely promising for routine clinical testing.

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Recent advances in the construction of functional nucleic acids with isothermal amplification for heavy metal ions sensor

Microchemical Journal ◽

10.1016/j.microc.2021.107077 ◽

2021 ◽

pp. 107077

Author(s):

Chen Liu ◽

Yujie Li ◽

Jinquan Liu ◽

Lifu Liao ◽

Renlong Zhou ◽

...

Keyword(s):

Heavy Metal ◽

Nucleic Acids ◽

Metal Ions ◽

Heavy Metal Ions ◽

Isothermal Amplification ◽

Recent Advances ◽

Functional Nucleic Acids

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A Sensitive Potentiometric Sensor for Isothermal Amplification-Coupled Detection of Nucleic Acids

Sensors ◽

10.3390/s18072277 ◽

2018 ◽

Vol 18 (7) ◽

pp. 2277

Author(s):

Kang-Ho Lee ◽

Dongkyu Lee ◽

Jongsu Yoon ◽

Ohwon Kwon ◽

Jaejong Lee

Keyword(s):

Nucleic Acids ◽

Real Time ◽

Surface Potential ◽

Pathogenic Bacteria ◽

Field Effect Transistors ◽

Potentiometric Sensor ◽

Isothermal Amplification ◽

Ring Oscillator ◽

Oxide Semiconductor ◽

High Signal

A disposable potentiometric sensor was newly developed for the amplification-coupled detection of nucleic acids. The hydrogen-ion is generally released during isothermal amplification of nucleic acids. The surface potential on the oxide-functionalized electrode of the extended gate was directly measured using full electrical circuits with the commercial metal-oxide semiconductor field-effect transistors (MOSFETs) and ring oscillator components, which resulted in cost-effective, portable and scalable real-time nucleic acid analysis. The current-starved ring oscillator changes surface potential to its frequency depending on the square of the variation in pH with a high signal-to-noise ratio during isothermal amplification. The device achieves a conversion rate of 20.5 kHz/mV and a detection resolution of 200 µV for the surface potential. It is demonstrated that the sensor successfully monitors in real-time isothermal amplification of the extracted nucleic acids from Salmonella pathogenic bacteria. The in situ variations in the frequency of the pH-sensitive sensor were compared with the results of both a conventional optical device and pH-meter during isothermal amplification.

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Competitive annealing mediated isothermal amplification of nucleic acids

The Analyst ◽

10.1039/c7an01569k ◽

2018 ◽

Vol 143 (3) ◽

pp. 639-642 ◽

Cited By ~ 2

Author(s):

Rui Mao ◽

Lifei Qi ◽

Jianjun Li ◽

Ming Sun ◽

Zhuo Wang ◽

...

Keyword(s):

Nucleic Acid ◽

Nucleic Acids ◽

High Specificity ◽

Isothermal Amplification ◽

Amplification Method

A novel nucleic acid isothermal amplification method with high specificity, efficiency and rapidity was developed.

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Qualitative and Quantitative Detection of Nucleic Acids of Infectious Agents by NASBA

Methods in DNA Amplification ◽

10.1007/978-1-4615-2530-1_11 ◽

1994 ◽

pp. 93-102

Author(s):

B. van Gemen ◽

T. Kievits ◽

P. F. Lens

Keyword(s):

Nucleic Acids ◽

Quantitative Detection ◽

Infectious Agents ◽

Qualitative And Quantitative

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Food Safety Analysis Using Electrochemical Biosensors

Foods ◽

10.3390/foods7090141 ◽

2018 ◽

Vol 7 (9) ◽

pp. 141 ◽

Cited By ~ 30

Author(s):

Geetesh Mishra ◽

Abbas Barfidokht ◽

Farshad Tehrani ◽

Rupesh Mishra

Keyword(s):

Food Safety ◽

Food Industry ◽

Analytical Techniques ◽

High Specificity ◽

Quantitative Detection ◽

Electrochemical Biosensors ◽

Food Contaminants ◽

Industry Standard ◽

Analytical Accuracy ◽

Analytical Tools

Rapid and precise analytical tools are essential for monitoring food safety and screening of any undesirable contaminants, allergens, or pathogens, which may cause significant health risks upon consumption. Substantial developments in analytical techniques have empowered the analyses and quantitation of these contaminants. However, conventional techniques are limited by delayed analysis times, expensive and laborious sample preparation, and the necessity for highly-trained workers. Therefore, prompt advances in electrochemical biosensors have supported significant gains in quantitative detection and screening of food contaminants and showed incredible potential as a means of defying such limitations. Apart from indicating high specificity towards the target analytes, these biosensors have also addressed the challenge of food industry by providing high analytical accuracy within complex food matrices. Here, we discuss some of the recent advances in this area and analyze the role and contributions made by electrochemical biosensors in the food industry. This article also reviews the key challenges we believe biosensors need to overcome to become the industry standard.

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