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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.


(a) Calibration graph for OTA analysis in HBB, pH 7.4 showing recovered fluorescence intensity percentage against OTA concentration. Inset showing the linear fit graph; (b) Bar graph representation of specificity studies of aptamer with OTB. Error bars were obtained from three parallel experiments.
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toxins-07-03771-f005: (a) Calibration graph for OTA analysis in HBB, pH 7.4 showing recovered fluorescence intensity percentage against OTA concentration. Inset showing the linear fit graph; (b) Bar graph representation of specificity studies of aptamer with OTB. Error bars were obtained from three parallel experiments.

Mentions: Under optimized experimental conditions, an aptamer assay was performed for the detection of OTA. Figure 5a presents the calibration curve of recovered fluorescence intensity percentage with a dynamic detection range of 1.5 nM to 20 µM. As shown in Figure 5a, the % recovery increased with increase in OTA concentration. The calibration curve was fitted using a linear equation and a line of equation obtained was y = 17.01x + 49.83 with R2 = 0.997. The good linearity was also obtained ranging from 1.5 nM to 1.0 μM with LOD of 1.5 nM with % R.S.D. = 3.65 (n = 3). The LOD was calculated based on the standard deviation of baseline signal. Similarly, the limit of quantification (LOQ) was calculated and found to be 3.1 nM. The obtained results suggest that the fluorescence recovery was due to the interaction of aptamer with OTA.


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)

(a) Calibration graph for OTA analysis in HBB, pH 7.4 showing recovered fluorescence intensity percentage against OTA concentration. Inset showing the linear fit graph; (b) Bar graph representation of specificity studies of aptamer with OTB. Error bars were obtained from three parallel experiments.
© Copyright Policy
Related In: Results  -  Collection

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

toxins-07-03771-f005: (a) Calibration graph for OTA analysis in HBB, pH 7.4 showing recovered fluorescence intensity percentage against OTA concentration. Inset showing the linear fit graph; (b) Bar graph representation of specificity studies of aptamer with OTB. Error bars were obtained from three parallel experiments.
Mentions: Under optimized experimental conditions, an aptamer assay was performed for the detection of OTA. Figure 5a presents the calibration curve of recovered fluorescence intensity percentage with a dynamic detection range of 1.5 nM to 20 µM. As shown in Figure 5a, the % recovery increased with increase in OTA concentration. The calibration curve was fitted using a linear equation and a line of equation obtained was y = 17.01x + 49.83 with R2 = 0.997. The good linearity was also obtained ranging from 1.5 nM to 1.0 μM with LOD of 1.5 nM with % R.S.D. = 3.65 (n = 3). The LOD was calculated based on the standard deviation of baseline signal. Similarly, the limit of quantification (LOQ) was calculated and found to be 3.1 nM. The obtained results suggest that the fluorescence recovery was due to the interaction of aptamer with OTA.

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.