Simple label-free fluorescence detection of apurinic/apyrimidinic endonuclease 1 activity and its inhibitor using the abasic site-binding fluorophore

A label-free fluorescence detection method for apurinic/apyrimidinic endonuclease 1 activity was reported based on the abasic site-binding fluorophore.

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A Simple and Label-Free Detection of As3+ using 3-nitro-L-tyrosine as an As3+-chelating Ligand

Sensors ◽

10.3390/s19132857 ◽

2019 ◽

Vol 19 (13) ◽

pp. 2857 ◽

Cited By ~ 5

Author(s):

Jin-Ho Park ◽

Gyuho Yeom ◽

Donggu Hong ◽

Eun-Jung Jo ◽

Chin-Ju Park ◽

...

Keyword(s):

Detection Method ◽

Color Change ◽

Specific Property ◽

Quantitative Detection ◽

Label Free ◽

Real Samples ◽

Real Water Samples ◽

Label Free Detection ◽

Reaction Stoichiometry ◽

Site Binding

A simple and rapid As3+ detection method using 3-nitro-L-tyrosine (N-Tyr) is reported. We discovered the specific property of N-Tyr, which specifically chelates As3+. The reaction between As3+ and N-Tyr induces a prompt color change to vivid yellow, concomitantly increasing the absorbance at 430 nm. The selectivity for As3+ is confirmed by competitive binding experiments with various metal ions (Hg2+, Pb2+, Cd2+, Cr3+, Mg2+, Ni2+, Cu2+, Fe2+, Ca2+, Zn2+, and Mn2+). Also, the N-Tyr binding site, binding affinity, and As3+/N-Tyr reaction stoichiometry are investigated. The specific reaction is utilized to design a sensor that enables the quantitative detection of As3+ in the 0.1–100 μM range with good linearity (R2 = 0.995). Furthermore, the method’s applicability for the analysis of real samples, e.g., tap and river water, is successfully confirmed, with good recoveries (94.32–109.15%) using As3+-spiked real water samples. We believe that our discovering and its application for As3+ analysis can be effectively utilized in environmental analyses such as those conducted in water management facilities, with simplicity, rapidity, and ease.

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Signal-Off and Signal-On Design for a Label-Free Aptasensor Based on Target-Induced Self-Assembly and Abasic-Site-Binding Ligands

Chemistry - A European Journal ◽

10.1002/chem.200901226 ◽

2009 ◽

Vol 15 (40) ◽

pp. 10375-10378 ◽

Cited By ~ 43

Author(s):

Zhiai Xu ◽

Yusuke Sato ◽

Seiichi Nishizawa ◽

Norio Teramae

Keyword(s):

Self Assembly ◽

Label Free ◽

Abasic Site ◽

Site Binding

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Target-controlled formation of silver nanoclusters in abasic site-incorporated duplex DNA for label-free fluorescence detection of theophylline

Nanoscale ◽

10.1039/c4nr00625a ◽

2014 ◽

Vol 6 (17) ◽

pp. 9977-9982 ◽

Cited By ~ 31

Author(s):

Ki Soo Park ◽

Seung Soo Oh ◽

H. Tom Soh ◽

Hyun Gyu Park

Keyword(s):

Fluorescence Detection ◽

Silver Nanoclusters ◽

Sensitive Detection ◽

Duplex Dna ◽

Label Free ◽

Abasic Site

A novel, label-free, fluorescence based sensor for the selective and sensitive detection of theophylline has been developed.

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A novel, label-free fluorescence detection method for the formation of G-quadruplex DNA based on DNA-templated silver nanoclusters

RSC Advances ◽

10.1039/c7ra02984e ◽

2017 ◽

Vol 7 (40) ◽

pp. 24628-24632 ◽

Cited By ~ 1

Author(s):

Jiaona Xu ◽

Chunying Wei

Keyword(s):

Fluorescence Detection ◽

Detection Method ◽

Silver Nanoclusters ◽

Label Free ◽

Quadruplex Dna ◽

G Quadruplex ◽

Ag Ncs

A novel, label-free fluorescence detection method was proposed for the formation of the G-quadruplex DNAs based on placing two DNA-Ag NCs together to light-up fluorescence.

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Alcohol Determination by HPLC with Postcolumn Derivatization Based on the Thiosulfate-catalyzed Reaction of Alcohols and Cerium(IV) and Fluorescence Detection of Cerium(III)

Current Analytical Chemistry ◽

10.2174/1573411016999201110094656 ◽

2020 ◽

Vol 16 ◽

Author(s):

Ikko Mikami ◽

Eri Shibayama ◽

Kengo Takagi

Keyword(s):

Detection Limit ◽

Fluorescence Detection ◽

Reaction Rate ◽

Detection Method ◽

Fluorescence Detector ◽

Reaction Solution ◽

Optimum Detection ◽

Postcolumn Derivatization ◽

Sensitive Method

Background: Determination of a reducing substance based on the reaction between Ce(IV) and a reducing substance and fluorescence detection of Ce(III) generated has been reported as a selective and sensitive method. However, this method could not be applied to the determination of alcohol due to the low reaction rate of alcohol and Ce(IV). Objective: We found that thiosulfate catalytically enhanced reaction of alcohols (such as, methanol, ethanol, and propanol) and Ce(IV). Utilizing this effect, we developed a new method for the determination of alcohols. Results: In the presence of thiosulfate, an increase in fluorescence intensity was detected by injecting alcohol at concentrations of several millimolar, whereas it was not observed even at the concentration of 10% v/v (2 M for ethanol) in the absence of thiosulfate. The optimum detection conditions were determined to be 4.0 mM Ce(IV) sulfate and 0.50 mM thiosulfate, and the detection limit (S/N = 3) of ethanol under these conditions was 1 mM. In the calibration curves, changes in the slope were observed when the alcohol concentrations were approximately 10–25 mM. Using a thiosulfate solution containing ethanol as the reaction solution, a calibration curve without any change in slope was obtained, although the concentration of ethanol at the detection limit increased. The alcohols in the liquor and fuel were successfully analyzed using the proposed detection method as a postcolumn reaction. Conclusion: This new alcohol detection method using a versatile fluorescence detector can be applied to the postcolumn reaction of HPLC omitting need of time-consuming pretreatment processes.

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Recognition of Bimolecular Logic Operation Pattern Based on a Solid-State Nanopore

Sensors ◽

10.3390/s21010033 ◽

2020 ◽

Vol 21 (1) ◽

pp. 33

Author(s):

Han Yan ◽

Zhen Zhang ◽

Ting Weng ◽

Libo Zhu ◽

Pang Zhang ◽

...

Keyword(s):

Self Assembly ◽

Detection Method ◽

Logic Gate ◽

Detection Methods ◽

Label Free ◽

Recognition Method ◽

Operation Pattern ◽

Simple Detection ◽

Dna Tetrahedron ◽

Marker Molecule

Nanopores have a unique advantage for detecting biomolecules in a label-free fashion, such as DNA that can be synthesized into specific structures to perform computations. This method has been considered for the detection of diseased molecules. Here, we propose a novel marker molecule detection method based on DNA logic gate by deciphering a variable DNA tetrahedron structure using a nanopore. We designed two types of probes containing a tetrahedron and a single-strand DNA tail which paired with different parts of the target molecule. In the presence of the target, the two probes formed a double tetrahedron structure. As translocation of the single and the double tetrahedron structures under bias voltage produced different blockage signals, the events could be assigned into four different operations, i.e., (0, 0), (0, 1), (1, 0), (1, 1), according to the predefined structure by logic gate. The pattern signal produced by the AND operation is obviously different from the signal of the other three operations. This pattern recognition method has been differentiated from simple detection methods based on DNA self-assembly and nanopore technologies.

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Assessment of a Semiquantitative Liquid Chromatography- Fluorescence Detection Method for the Determination of Paralytic Shellfish Poisoning Toxin Levels in Bivalve Molluscs from Great Britain

Journal of AOAC International ◽

10.5740/jaoacint.13-381 ◽

2014 ◽

Vol 97 (2) ◽

pp. 492-497 ◽

Cited By ~ 3

Author(s):

Andrew D Turner ◽

Monika Dhanji-Rapkova ◽

Clothilde Baker ◽

Myriam Algoet

Keyword(s):

Great Britain ◽

Fluorescence Detection ◽

Detection Method ◽

Reference Method ◽

Paralytic Shellfish Poisoning ◽

Official Method ◽

Shellfish Poisoning ◽

Bivalve Molluscs ◽

Paralytic Shellfish

Abstract AOAC Official Method 2005.06 precolumn oxidation LC-fluorescence detection method has been used for many years for the detection and quantitation of paralytic shellfish poisoning (PSP) toxins in bivalve molluscs. After extensive single- and multiple-laboratory validation, the method has been slowly gaining acceptance worldwide as a useful and practical tool for official control testing. In Great Britain, the method has become routine since 2008, with no requirement since then for reverting back to the bioassay reference method. Although the method has been refined to be semiautomated, faster, and more reproducible, the quantitation step can be complex and time-consuming. An alternative approach was developed to utilize the qualitative screening results for generatinga semiquantitative results assessment. Data obtained over 5 years enabled the comparison of semiquantitative and fully quantitative PSP results in over 15 000 shellfish samples comprising eight different species showed that the semiquantitative approach resulted in over-estimated paralytic shellfish toxin levels by an average factor close to two in comparison with the fully quantified levels. No temporal trends were observed in the data or relating to species type, with the exception of surf clams. The comparison suggested a semiquantitative threshold of 800 μg saxitoxin (STX) eq/kg should provide a safe limitfor the determination of samples to be forwarded to full quantitation. However, the decision was taken to halve this limit to include an additional safety factor of 2, resulting in the use of a semiquantitative threshold of 400 μg STX eq/kg. Implementation of the semiquantitative method into routine testing would result in a significant reduction in the numbers of samples requiring quantitation and have a positive impact on the overall turnaround of reported PSP results. The refined method would be appropriate for any monitoring laboratory faced with high throughput requirements.

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