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Titanium Dioxide Nanoparticles (TiO₂) Quenching Based Aptasensing Platform: Application to Ochratoxin A Detection.

Sharma A, Hayat A, Mishra RK, Catanante G, Bhand S, Marty JL - Toxins (Basel) (2015)

Bottom Line: When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO₂, resulting in fluorescence recovery.Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis.However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

View Article: PubMed Central - PubMed

Affiliation: BAE Laboratory, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan 66860, France. sgbhand@gmail.com.

ABSTRACT
We demonstrate for the first time, the development of titanium dioxide nanoparticles (TiO₂) quenching based aptasensing platform for detection of target molecules. TiO₂ quench the fluorescence of FAM-labeled aptamer (fluorescein labeled aptamer) upon the non-covalent adsorption of fluorescent labeled aptamer on TiO₂ surface. When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO₂, resulting in fluorescence recovery. As a proof of concept, an assay was employed for detection of Ochratoxin A (OTA). At optimized experimental condition, the obtained limit of detection (LOD) was 1.5 nM with a good linearity in the range 1.5 nM to 1.0 µM for OTA. The obtained results showed the high selectivity of assay towards OTA without interference to structurally similar analogue Ochratoxin B (OTB). The developed aptamer assay was evaluated for detection of OTA in beer sample and recoveries were recorded in the range from 94.30%-99.20%. Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis. However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

No MeSH data available.


Related in: MedlinePlus

Schematic representation of TiO2 quenching based sensing platform for target molecule detection. (a) In the absence of target analyte, adsorption of FAM-labeled aptamer on TiO2 surface led fluorescence quenching; (b) In the presence of target analyte, the anti-parallel G-quadruplex structure form decrease adsorption and fluorescence recovered.
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toxins-07-03771-f001: Schematic representation of TiO2 quenching based sensing platform for target molecule detection. (a) In the absence of target analyte, adsorption of FAM-labeled aptamer on TiO2 surface led fluorescence quenching; (b) In the presence of target analyte, the anti-parallel G-quadruplex structure form decrease adsorption and fluorescence recovered.

Mentions: In the present work, we demonstrate the development of TiO2 quenching based aptasensing platform for detection of target molecule based on TiO2-FAM quenching mechanism as depicted in Figure 1. As shown in the Figure 1a, in the absence of a target molecule, adsorption of FAM-labeled aptamer on TiO2 surface results in fluorescence quenching of labeled aptamer. The quenching mechanism of TiO2-FAM system can be attributed to the large band gap semiconductor behavior of TiO2 and the electrostatic interaction involving Ti-O bond between TiO2 and FAM, resulting fluorescence quenching through the acceptance of electrons from excited FAM molecules [30,37,38]. In the presence of a target molecule, the target induces conformational change in aptamer’s structure led to the formation of anti-parallel G-quadruplex structure, which decreases the adsorption and weakens the quenching interaction between FAM and TiO2. These induced conformational changes in aptamer structure results in significant recovery of fluorescence in comparison to the fluorescence quenched in the absence of target molecules as shown in Figure 1b. Thus, by monitoring the degree of fluorescence recovered, the presence of target molecule could be measured quantitatively.


Titanium Dioxide Nanoparticles (TiO₂) Quenching Based Aptasensing Platform: Application to Ochratoxin A Detection.

Sharma A, Hayat A, Mishra RK, Catanante G, Bhand S, Marty JL - Toxins (Basel) (2015)

Schematic representation of TiO2 quenching based sensing platform for target molecule detection. (a) In the absence of target analyte, adsorption of FAM-labeled aptamer on TiO2 surface led fluorescence quenching; (b) In the presence of target analyte, the anti-parallel G-quadruplex structure form decrease adsorption and fluorescence recovered.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591649&req=5

toxins-07-03771-f001: Schematic representation of TiO2 quenching based sensing platform for target molecule detection. (a) In the absence of target analyte, adsorption of FAM-labeled aptamer on TiO2 surface led fluorescence quenching; (b) In the presence of target analyte, the anti-parallel G-quadruplex structure form decrease adsorption and fluorescence recovered.
Mentions: In the present work, we demonstrate the development of TiO2 quenching based aptasensing platform for detection of target molecule based on TiO2-FAM quenching mechanism as depicted in Figure 1. As shown in the Figure 1a, in the absence of a target molecule, adsorption of FAM-labeled aptamer on TiO2 surface results in fluorescence quenching of labeled aptamer. The quenching mechanism of TiO2-FAM system can be attributed to the large band gap semiconductor behavior of TiO2 and the electrostatic interaction involving Ti-O bond between TiO2 and FAM, resulting fluorescence quenching through the acceptance of electrons from excited FAM molecules [30,37,38]. In the presence of a target molecule, the target induces conformational change in aptamer’s structure led to the formation of anti-parallel G-quadruplex structure, which decreases the adsorption and weakens the quenching interaction between FAM and TiO2. These induced conformational changes in aptamer structure results in significant recovery of fluorescence in comparison to the fluorescence quenched in the absence of target molecules as shown in Figure 1b. Thus, by monitoring the degree of fluorescence recovered, the presence of target molecule could be measured quantitatively.

Bottom Line: When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO₂, resulting in fluorescence recovery.Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis.However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

View Article: PubMed Central - PubMed

Affiliation: BAE Laboratory, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, Perpignan 66860, France. sgbhand@gmail.com.

ABSTRACT
We demonstrate for the first time, the development of titanium dioxide nanoparticles (TiO₂) quenching based aptasensing platform for detection of target molecules. TiO₂ quench the fluorescence of FAM-labeled aptamer (fluorescein labeled aptamer) upon the non-covalent adsorption of fluorescent labeled aptamer on TiO₂ surface. When OTA interacts with the aptamer, it induced aptamer G-quadruplex complex formation, weakens the interaction between FAM-labeled aptamer and TiO₂, resulting in fluorescence recovery. As a proof of concept, an assay was employed for detection of Ochratoxin A (OTA). At optimized experimental condition, the obtained limit of detection (LOD) was 1.5 nM with a good linearity in the range 1.5 nM to 1.0 µM for OTA. The obtained results showed the high selectivity of assay towards OTA without interference to structurally similar analogue Ochratoxin B (OTB). The developed aptamer assay was evaluated for detection of OTA in beer sample and recoveries were recorded in the range from 94.30%-99.20%. Analytical figures of the merits of the developed aptasensing platform confirmed its applicability to real samples analysis. However, this is a generic aptasensing platform and can be extended for detection of other toxins or target analyte.

No MeSH data available.


Related in: MedlinePlus