Fluorometric graphene oxide-based detection of Salmonella enteritis using a truncated DNA aptamer

The 27-nucleotide DNA aptamer for adenosine and ATP, originally selected by the Szostak lab in 1995, has been a very popular model system for biosensor development. This unique aptamer has two target binding sites, and we recently showed that it is possible to remove either site while the other one still retains binding. From an analytical perspective, tuning the number of binding sites has important implications in modulating sensitivity of the resulting biosensors. In this work, we report that the engineered one-site aptamer showed excellent signaling properties with a 2.6-fold stronger signal intensity and also a 4.2-fold increased detection limit compared with the wild-type two-site aptamer. The aptamer has a hairpin structure, and the length of the hairpin stem was systematically varied for the one-site aptamers. Isothermal titration calorimetry and a label-free fluorescence signaling method with graphene oxide and SYBR Green I were respectively used to evaluate binding and sensor performance. Although longer stemmed aptamers produced better adenosine binding affinity, the signaling was quite independent of the stem length as long as more than three base pairs were left. This was explained by the higher affinity of binding to GO by the longer aptamers, cancelling out the higher affinity for adenosine binding. This work further confirms the analytical applications of such one-site adenosine aptamers, which are potentially useful for improved ATP imaging and for developing new biosensors.

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DNase I enzyme-aided fluorescence signal amplification based on graphene oxide-DNA aptamer interactions for colorectal cancer exosome detection

Talanta ◽

10.1016/j.talanta.2018.02.083 ◽

2018 ◽

Vol 184 ◽

pp. 219-226 ◽

Cited By ~ 48

Author(s):

Hui Wang ◽

Hui Chen ◽

Zhipeng Huang ◽

Tengda Li ◽

Anmei Deng ◽

...

Keyword(s):

Colorectal Cancer ◽

Graphene Oxide ◽

Signal Amplification ◽

Dnase I ◽

Dna Aptamer ◽

Fluorescence Signal ◽

Fluorescence Signal Amplification

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Aptamer-based cocaine assay using a nanohybrid composed of ZnS/Ag2Se quantum dots, graphene oxide and gold nanoparticles as a fluorescent probe

Microchimica Acta ◽

10.1007/s00604-019-4101-6 ◽

2020 ◽

Vol 187 (2) ◽

Cited By ~ 7

Author(s):

Oluwasesan Adegoke ◽

Magda A. Pereira-Barros ◽

Svetlana Zolotovskaya ◽

Amin Abdolvand ◽

Niamh Nic Daeid

Keyword(s):

Quantum Dots ◽

Gold Nanoparticles ◽

Graphene Oxide ◽

Dna Aptamer ◽

Localized Surface Plasmon ◽

Fluorescence Signal ◽

Dependent Manner ◽

Binding Interaction ◽

Experimental Conditions ◽

Fluorescent Nanoprobe

AbstractAuthors report on a new fluoro-graphene-plasmonic nanohybrid aptamer-based fluorescent nanoprobe for cocaine. To construct the nanoprobe, newly synthesized glutathione-capped ZnS/Ag2Se quantum dots (QDs) were first conjugated to graphene oxide (GO) to form a QD-GO nanocomposite. The binding interaction resulted in a fluorescence turn-ON. Thereafter, cetyltrimethylammonium bromide (CTAB)-gold nanoparticles (AuNPs) were directly adsorbed on the QD-GO nanocomposite to form a novel QD-GO-CTAB-AuNP nanohybrid assembly that resulted in a fluorescence turn-OFF. Streptavidin (strep) was then adsorbed on the QDs-GO-CTAB-AuNP nanohybrid assembly which allowed binding to a biotinylated MNS 4.1 anticocaine DNA aptamer (B) receptor. The addition of cocaine into the strep-B-QDs-GO-CTAB-AuNP aptamer nanoprobe system aided affinity to the aptamer receptor and in turn turned on the fluorescence of the nanoprobe in a concentration-dependent manner. Under optimum experimental conditions, we found the strep-B-QD-GO-CTAB-AuNP to be far superior in its sensitivity to cocaine than the tested strep-B-QDs (no GO and CTAB-AuNPs), strep-B-QD-CTAB-AuNP (no GO) and strep-B-QD-GO (no CTAB-AuNP). In addition, the investigation of localized surface plasmon resonance (LSPR) amplified signal from tested plasmonic NPs shows that CTAB-AuNPs was far superior in amplifying the fluorescence signal of the nanoprobe. A detection limit of 4.6 nM (1.56 ng.mL−1), rapid response time (~2 min) and excellent selectivity against other drugs, substances and cocaine metabolites was achieved. The strep-B-QD-GO-CTAB-AuNP aptamer-based fluorescent nanoprobe was successfully applied for the determination of cocaine in seized adulterated cocaine samples.

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Graphene oxide and DNA aptamer based sub-nanomolar potassium detecting optical nanosensor

Nanotechnology ◽

10.1088/1361-6528/aa79e0 ◽

2017 ◽

Vol 28 (32) ◽

pp. 325502 ◽

Cited By ~ 7

Author(s):

Debopam Datta ◽

Ketaki Sarkar ◽

Souvik Mukherjee ◽

Xenia Meshik ◽

Michael A Stroscio ◽

...

Keyword(s):

Graphene Oxide ◽

Dna Aptamer

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Electrochemical Detection of Ultratrace Lead Ion through Attaching and Detaching DNA Aptamer from Electrochemically Reduced Graphene Oxide Electrode

Nanomaterials ◽

10.3390/nano9060817 ◽

2019 ◽

Vol 9 (6) ◽

pp. 817 ◽

Cited By ~ 9

Author(s):

Su Hwan Yu ◽

Chang-Seuk Lee ◽

Tae Hyun Kim

Keyword(s):

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Dna Aptamer ◽

Lead Ion ◽

Oxide Electrode ◽

Quadruplex Dna ◽

Simple Strategy ◽

Reduced Graphene ◽

Electrochemically Reduced Graphene Oxide ◽

G Quadruplex

This paper describes a simple strategy for the ultratrace level detection of Pb2+ ion based on G-quadruplex DNA and an electrochemically reduced graphene oxide (ERGO) electrode. First, ERGO was formed on a glassy carbon electrode (GCE) by the reduction of graphene oxide (GO) using cyclic voltammetry. Subsequently, a methylene blue (MB)-tagged, guanine-rich DNA aptamer (Apt) was attached to the surface of ERGO via π-π interaction, leading to the Apt-modified ERGO electrode. The presence of Pb2+ could generate the folding of Apt to a G-quadruplex structure. The formation of G-quadruplex resulted in detaching the Apt from the ERGO/GCE, leading to a change in redox current of the MB tag. Electrochemical measurements showed the proposed sensor had an exceptional sensitivity for Pb2+ with a linear range from 10−15 to 10−9 M and a detection limit of 0.51 fM. The sensor also exhibited high selectivity for Pb2+, as well as many other advantages, such as stability, reproducibility, regeneration, as well as simple fabrication and operation processes.

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