scholarly journals Label-Free Detection of Zeptomol miRNA via Peptide Nucleic Acid Hybridization Using Novel Cyclic Voltammetry Method

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 836
Author(s):  
Shintaro Takase ◽  
Kouta Miyagawa ◽  
Hisafumi Ikeda
Keyword(s):  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Microelectrode Array ◽  
Pcr Amplification ◽  
Nucleic Acid Hybridization ◽  
Detection Sensitivity ◽  
Cyclic Voltammograms ◽  
Dna Duplexes ◽  
Label Free ◽  
Label Free Detection

To harness the applicability of microribonucleic acid (miRNA) as a cancer biomarker, the detection sensitivity of serum miRNA needs to be improved. This study evaluated the detection sensitivity of miRNA hybridization using cyclic voltammograms (CVs) and microelectrode array chips modified with peptide nucleic acid (PNA) probes and 6-hydroxy-1-hexanethiol. We investigated the PNA probe modification pattern on array chips using fluorescently labeled cDNA. The pattern was not uniformly spread over the working electrode (WE) and had a one-dimensional swirl-like pattern. Accordingly, we established a new ion-channel sensor model wherein the WE is negatively biased through the conductive π–π stacks of the PNA/DNA duplexes. This paper discusses the mechanism underlying the voltage shift in the CV curves based on the electric double-layer capacitance. Additionally, the novel hybridization evaluation parameter ΔE is introduced. Compared to conventional evaluation using oxidation current changes, ΔE was more sensitive. Using ΔE and a new hybridization system for ultrasmall amounts of aqueous solutions (as low as 35 pL), 140 zeptomol label-free miRNA were detected without polymerase chain reaction (PCR) amplification at an adequate sensitivity. Herein, the differences in the target molar amount and molar concentration are elucidated from the viewpoint of hybridization sensitivity.

Peptide Nucleic Acid-Mediated Aggregation of Reduced Graphene Oxides and Label-Free Detection of DNA Mutation

2014 ◽  
Vol 118 (23) ◽  
pp. 6297-6301 ◽  
Author(s):  
Taegyeong Kang ◽  
Hoon Choi ◽  
Sang-Woo Joo ◽  
So Yeong Lee ◽  
Kyong-Ah Yoon ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Label Free ◽  
Graphene Oxides ◽  
Dna Mutation ◽  
Reduced Graphene ◽  
Label Free Detection ◽  
Reduced Graphene Oxides

scholarly journals Affinity Sensors for the Diagnosis of COVID-19

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 390
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Arunas Ramanavicius
Keyword(s):  
Field Effect Transistors ◽  
Resonance Field ◽  
Analytical Signal ◽  
Nucleic Acid Hybridization ◽  
Detection Methods ◽  
Label Free ◽  
Infected People ◽  
Label Free Detection ◽  
Main Instrument ◽  
Antigen Antibody

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxygen species (ROS) level are mostly used for the generation of analytical signals, which can be accurately measured by electrochemical, optical, surface plasmon resonance, field-effect transistors, and some other methods and transducers. Electrochemical biosensors are the most consistent with the general trend towards, acceleration, and simplification of the bioanalytical process. These biosensors mostly are based on the determination of antigen-antibody interaction and are robust, sensitive, accurate, and sometimes enable label-free detection of an analyte. Along with the specification of biosensors, we also provide a brief overview of generally used testing techniques, and the description of the structure, life cycle and immune host response to SARS-CoV-2, and some deeper details of analytical signal detection principles.

Label-free detection of nucleic acid and protein microarrays by scanning Kelvin nanoprobe

2005 ◽  
Vol 20 (8) ◽  
pp. 1471-1481 ◽  
Author(s):  
Michael Thompson ◽  
Larisa-Emilia Cheran ◽  
Mingquan Zhang ◽  
Melissa Chacko ◽  
Hong Huo ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Protein Microarrays ◽  
Label Free ◽  
Label Free Detection

scholarly journals Synthesis and optical properties of pyrrolidinyl peptide nucleic acid carrying a clicked Nile red label

2014 ◽  
Vol 10 ◽  
pp. 2166-2174 ◽  
Author(s):  
Nattawut Yotapan ◽  
Chayan Charoenpakdee ◽  
Pawinee Wathanathavorn ◽  
Boonsong Ditmangklo ◽  
Hans-Achim Wagenknecht ◽  
...  
Keyword(s):  
Optical Properties ◽  
Nucleic Acid ◽  
Peptide Nucleic Acid ◽  
Nile Red ◽  
Fluorescent Label ◽  
Dna Duplexes ◽  
Enhanced Fluorescence ◽  
Structure And Dynamics ◽  
Close Proximity ◽  
Base Insertion

DNA or its analogues with an environment-sensitive fluorescent label are potentially useful as a probe for studying the structure and dynamics of nucleic acids. In this work, pyrrolidinyl peptide nucleic acid (acpcPNA) was labeled at its backbone with Nile red, a solvatochromic benzophenoxazine dye, by means of click chemistry. The optical properties of the Nile red-labeled acpcPNA were investigated by UV–vis and fluorescence spectroscopy in the absence and in the presence of DNA. In contrast to the usual quenching observed in Nile red-labeled DNA, the hybridization with DNA resulted in blue shifting and an enhanced fluorescence regardless of the neighboring bases. More pronounced blue shifts and fluorescence enhancements were observed when the DNA target carried a base insertion in close proximity to the Nile red label. The results indicate that the Nile red label is located in a more hydrophobic environment in acpcPNA–DNA duplexes than in the single-stranded acpcPNA. The different fluorescence properties of the acpcPNA hybrids of complementary DNA and DNA carrying a base insertion are suggestive of different interactions between the Nile red label and the duplexes.

Label-free DNA biosensor based on a peptide nucleic acid-functionalized microstructured optical fiber-Bragg grating

2013 ◽  
Vol 18 (5) ◽  
pp. 057004 ◽  
Author(s):  
Alessandro Candiani ◽  
Alessandro Bertucci ◽  
Sara Giannetti ◽  
Maria Konstantaki ◽  
Alex Manicardi ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Optical Fiber ◽  
Fiber Bragg Grating ◽  
Peptide Nucleic Acid ◽  
Dna Biosensor ◽  
Bragg Grating ◽  
Label Free ◽  
Microstructured Optical Fiber ◽  
Free Dna ◽  
Optical Fiber Bragg Grating
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