scholarly journals Nucleic-Acid-Binding Chromophores as Efficient Indicators of Aptamer-Target Interactions

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Kwabena Sarpong ◽  
Bhaskar Datta
Keyword(s):  
Nucleic Acid ◽  
High Sensitivity ◽  
Covalent Modification ◽  
Fluorescence Signal ◽  
Nucleic Acid Binding ◽  
Sensitivity And Selectivity ◽  
Target Molecules ◽  
Diagnostic Applications ◽  
The Stability ◽  
Simple Format

The binding affinity and specificity of nucleic acid aptamers have made them valuable candidates for use as sensors in diagnostic applications. In particular, chromophore-functionalized aptamers offer a relatively simple format for detection and quantification of target molecules. We describe the use of nucleic-acid-staining reagents as an effective tool for detecting and signaling aptamer-target interactions. Aptamers varying in size and structure and targeting a range of molecules have been used in conjunction with commercially available chromophores to indicate and quantify the presence of cognate targets with high sensitivity and selectivity. Our assay precludes the covalent modification of nucleic acids and relies on the differential fluorescence signal of chromophores when complexed with aptamers with or without their cognate target. We also evaluate factors that are critical for the stability of the complex between the aptamer and chromophore in presence or absence of target molecules. Our results indicate the possibility of controlling those factors to enhance the sensitivity of target detection by the aptamers used in such assays.

Promoter engineering improves transcription efficiency in biomolecular assays

2021 ◽  
Vol 57 (13) ◽  
pp. 1619-1622
Author(s):  
Jisu Woo ◽  
Jung Ho Kim ◽  
Seokjoon Kim ◽  
Ki Soo Park
Keyword(s):  
High Sensitivity ◽  
Rnase H ◽  
Activity Assay ◽  
T7 Promoter ◽  
Promoter Engineering ◽  
Transcription Efficiency ◽  
Sensitivity And Selectivity ◽  
Biomolecular Assays ◽  
Diagnostic Applications

A novel T7 promoter with improved transcription efficiency has been developed. It is more suitable for diagnostic applications due to its small size and is successfully used for an RNase H activity assay with high sensitivity and selectivity.

Improved Detection of Hg2+ in Aqueous Solution with High Sensitivity and Selectivity by Using Mercury-Specific DNA, Sybr Green I and Gold Nanoparticles

2011 ◽  
Vol 239-242 ◽  
pp. 934-939
Author(s):  
Hui Xu ◽  
Shuli Gao ◽  
Jian Nong Chen ◽  
Quan Wen Liu
Keyword(s):  
Gold Nanoparticles ◽  
High Sensitivity ◽  
Sybr Green ◽  
Sybr Green I ◽  
Fluorescence Signal ◽  
Potassium Ions ◽  
Label Free ◽  
Turn On ◽  
Sensitivity And Selectivity ◽  
Fluorescence Turn On

We report a label-free, fast, fluorescence turn on assay for Hg2+detecton by using mercury-specific DNA (MSD), Sybr Green I (SG) and gold nanoparticles (AuNPs). SG efficiently discriminates MSD and MSD/Hg2+complex. The addition of gold nanoparticle decreases the background fluorescence signal further for MSD. The fluorescence intensity of MSD/Hg2+complex keeps constant after addition of AuNPs. This property improves the signal-to-background ratio and decreases the detection limitation further. In addition, the method shows improved selectivity compared with that in the absence of AuNPs. This strategy could be applied to the detection of potassium ions and showed good generality.

scholarly journals A FRET-ICT Dual-Modulated Ratiometric Fluorescence Sensor for Monitoring and Bio-Imaging of Cellular Selenocysteine

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 4999
Author(s):  
Zongcheng Wang ◽  
Chenhong Hao ◽  
Xiaofang Luo ◽  
Qiyao Wu ◽  
Chengliang Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Limit Of Detection ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
High Sensitivity ◽  
Fluorescence Sensor ◽  
Quantitative Detection ◽  
Fluorescence Signal ◽  
Ratiometric Fluorescence ◽  
Sensitivity And Selectivity

Since the fluctuation of cellular selenocysteine (Sec) concentration plays an all-important role in the development of numerous human disorders, the real-time fluorescence detection of Sec in living systems has attracted plenty of interest during the past decade. In order to obtain a faster and more sensitive small organic molecule fluorescence sensor for the Sec detection, a new ratiometric fluorescence sensor Q7 was designed based on the fluorescence resonance energy transfer (FRET) strategy with coumarin fluorophore as energy donor and 4-hydroxy naphthalimide fluorophore (with 2,4-dinitrobenzene sulfonate as fluorescence signal quencher and Sec-selective recognition site) as an energy acceptor. The sensor Q7 exhibited only a blue fluorescence signal, and displayed two well distinguished emission bands (blue and green) in the presence of Sec with ∆λ of 68 nm. Moreover, concentrations ranging of quantitative detection of Sec of Q7 was from 0 to 45 μM (limit of detection = 6.9 nM), with rapid ratiometric response, high sensitivity and selectivity capability. Impressively, the results of the living cell imaging test demonstrated Q7 has the potentiality of being an ideal sensor for real-time Sec detection in biosystems.

scholarly journals Recent Development of Aptamer Sensors for the Quantification of Aflatoxin B1

2019 ◽  
Vol 9 (11) ◽  
pp. 2364 ◽  
Author(s):  
Yongmei Jia ◽  
Guohua Zhou ◽  
Peilian Liu ◽  
Zhiguo Li ◽  
Biao Yu
Keyword(s):  
Nucleic Acid ◽  
Food Quality ◽  
Aflatoxin B1 ◽  
High Selectivity ◽  
High Sensitivity ◽  
Nucleic Acid Sequence ◽  
Recent Developments ◽  
Contaminated Food ◽  
Sensitivity And Selectivity ◽  
Labor Consuming

Aflatoxin B1 (AFB1) is one of the most frequently-found mycotoxins in contaminated food. As the content of mycotoxins is particularly low in food, the development of probes to detect AFB1 in foods with high sensitivity and selectivity is an urgent social need for the evaluation of food quality. Numerous techniques have been developed to monitor AFB1. Nevertheless, most of them require cumbersome, labor-consuming, and sophisticated instruments, which have limited their application. An aptamer is a single, short nucleic acid sequence that is capable of recognizing different targets. Owing to their unique properties, aptamers have been considered as alternatives to antibodies. Aptasensors are considered to be an emerging strategy for the quantification of aflatoxin B1 with high selectivity and sensitivity. In this review, we summarize recent developments in colormetric, electrochemical, SERS, and fluorescent aptasensors for the quantification of AFB1. Finally, the perspectives and current challenges of aptasensors for AFB1 are outlined.

scholarly journals Femtomolar and locus-specific detection of N6-methyladenine in DNA by integrating double-hindered replication and nucleic acid-functionalized MB@Zr-MOF

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qingyuan Zheng ◽  
Tong Wang ◽  
Xinmin Li ◽  
Husun Qian ◽  
Xintong Bian ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Dna Polymerase ◽  
Dna Analysis ◽  
Electrochemical Biosensor ◽  
High Sensitivity ◽  
High Porosity ◽  
Specific Detection ◽  
Sensitivity And Selectivity ◽  
Negative Surface ◽  
A Site

AbstractIn this study, a novel electrochemical biosensor was constructed for ultrasensitive and locus-specific detection of N6-Methyladenine (m6A) in DNA using double-hindered replication and nucleic acid-coated methylene blue (MB)@Zr-MOF. Based on the combination of m6A-impeded replication and AgI-mediated mismatch replication, this mode could effectively stop the extension of the strand once DNA polymerase encountered m6A site, which specifically distinguish the m6A site from natural A site in DNA. Also, Zr-MOF with high porosity and negative surface potential features was carefully chose to load cationic MB, resulting a stable and robust MB@Zr-MOF electrochemical tag. As a result, the developed biosensor exhibited a wide linear range from 1 fM to 1 nM with detection limit down to 0.89 fM. Profiting from the high sensitivity and selectivity, the biosensing strategy revealed good applicability, which had been demonstrated by quantitating m6A DNA at specific site in biological matrix. Thus, the biosensor provides a promising platform for locus-specific m6A DNA analysis. Graphical Abstract

scholarly journals A simple, high-throughput stabilization assay to test HIV-1 uncoating inhibitors

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Alžběta Dostálková ◽  
Romana Hadravová ◽  
Filip Kaufman ◽  
Ivana Křížová ◽  
Kryštof Škach ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
High Throughput ◽  
Reverse Transcription ◽  
Fluorescence Signal ◽  
Double Stranded Dna ◽  
Capsid Shell ◽  
Cell Genome ◽  
The Stability ◽  
Hiv 1

AbstractShortly after entering the cell, HIV-1 copies its genomic RNA into double-stranded DNA in a process known as reverse transcription. This process starts inside a core consisting of an enclosed lattice of capsid proteins that protect the viral RNA from cytosolic sensors and degradation pathways. To accomplish reverse transcription and integrate cDNA into the host cell genome, the capsid shell needs to be disassembled, or uncoated. Premature or delayed uncoating attenuates reverse transcription and blocks HIV-1 infectivity. Small molecules that bind to the capsid lattice of the HIV-1 core and either destabilize or stabilize its structure could thus function as effective HIV-1 inhibitors. To screen for such compounds, we modified our recently developed FAITH assay to allow direct assessment of the stability of in vitro preassembled HIV-1 capsid-nucleocapsid (CANC) tubular particles. This new assay is a high-throughput fluorescence method based on measuring the amount of nucleic acid released from CANC complexes under disassembly conditions. The amount of disassembled CANC particles and released nucleic acid is proportional to the fluorescence signal, from which the relative percentage of CANC stability can be calculated. We consider our assay a potentially powerful tool for in vitro screening for compounds that alter HIV disassembly.

Lateral flow nucleic acid biosensor for Cu2+ detection in aqueous solution with high sensitivity and selectivity

2010 ◽  
Vol 46 (47) ◽  
pp. 9043 ◽  
Author(s):  
Zhiyuan Fang ◽  
Jing Huang ◽  
Puchang Lie ◽  
Zhuo Xiao ◽  
Chuanyan Ouyang ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Nucleic Acid ◽  
High Sensitivity ◽  
Lateral Flow ◽  
Sensitivity And Selectivity

scholarly journals Recent Advances in Sensing Applications of Molecularly Imprinted Photonic Crystals

2021 ◽  
Vol 9 ◽  
Author(s):  
Jing Fan ◽  
Lili Qiu ◽  
Yu Qiao ◽  
Min Xue ◽  
Xiao Dong ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
High Sensitivity ◽  
Molecularly Imprinted ◽  
Naked Eye ◽  
Sensing Applications ◽  
Recent Advances ◽  
Molecular Imprinting Technology ◽  
Sensitivity And Selectivity ◽  
Target Molecules ◽  
Naked Eye Detection

Photonic crystals (PhCs) with a brightly colored structure are novel materials and are widely used in chemical and biological sensing. Combining PhCs with molecular imprinting technology (MIT), the molecularly imprinted PhC (MIPC) sensors are fabricated, which can specifically recognize the target molecules. Aside from high sensitivity and selectivity, the MIPC sensors could recognize the naked eye detection because of its optical properties. In this review, an overview of recent advances in sensing applications of MIPC sensors including the responsive mechanisms, application in environmental monitoring, and the application to human health were illustrated. The MIPC sensors all responded to the analytes specifically and also showed high sensitivity in real samples, which provided a method to realize the rapid, convenient, naked eye, and real-time detection. Furthermore, the current limitations and potential future directions of MIPC sensors were also discussed.

scholarly journals Femtomolar And Locus-Specific Detection of N6-Methyladenine In DNA By Integrating Double-Hindered Replication And Nucleic Acid-Functionalized MB@Zr-MOF

2021 ◽  
Author(s):  
Qingyuan Zheng ◽  
Tong Wang ◽  
Xinmin Li ◽  
Husun Qian ◽  
Xintong Bian ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Dna Polymerase ◽  
Dna Analysis ◽  
Electrochemical Biosensor ◽  
High Sensitivity ◽  
High Porosity ◽  
Specific Detection ◽  
Sensitivity And Selectivity ◽  
Negative Surface ◽  
A Site

Abstract In this study, a novel electrochemical biosensor was constructed for ultrasensitive and locus-specific detection of N6-Methyladenine (m6A) in DNA using double-hindered replication and nucleic acid-coated methylene blue (MB)@Zr-MOF. Based on the combination of m6A-impeded replication and AgI-mediated mismatch replication, this mode could effectively stop the extension of the strand once DNA polymerase encountered m6A site, which specifically distinguish the m6A site from natural A site in DNA. Also, Zr-MOF with high porosity and negative surface potential features was carefully chose to load cationic MB, resulting a stable and robust MB@Zr-MOF electrochemical tag. As a result, the developed biosensor exhibited a wide linear range from 1 fM to 1 nM with detection limit down to 0.89 fM. Profiting from the high sensitivity and selectivity, the biosensing strategy revealed good applicability, which had been demonstrated by quantitating m6A DNA at specific site in biological matrix. Thus, the biosensor provides a promising platform for locus-specific m6A DNA analysis.

2D luminescent metal–organic framework: efficient and highly selective detection of 2,4,6-trinitrophenol at the ppb level

CrystEngComm ◽  
2021 ◽  
Author(s):  
Ming Yue Fan ◽  
Peng Fu ◽  
Jiao Li ◽  
Zhong Min Su ◽  
Xiao Li ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
High Sensitivity ◽  
Fluorescence Signal ◽  
Selective Detection ◽  
Quenching Mechanism ◽  
Naked Eye ◽  
Sensitivity And Selectivity ◽  
Metal Organic ◽  
Organic Framework

A 2D Cd-MOF (CUST-531) was reported as a sensor to detect TNP with high sensitivity and selectivity. The quenching mechanism is the turn-off response of the fluorescence signal, which can be observed by the naked eye under UV-vis lamp irradiation.

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