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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

(A) UV absorption spectra of (a) TiO2; (b) Aptamer; (c) Aptamer-target complex (in absence of TiO2); (d) Aptamer-target complex (in presence of TiO2); and (e) Aptamer-TiO2 complex; (B) Fluorescence imaging of (i) FAM-aptamer; (ii) aptamer-TiO2; and (iii) aptamer-target complex (in presence of TiO2).
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toxins-07-03771-f002: (A) UV absorption spectra of (a) TiO2; (b) Aptamer; (c) Aptamer-target complex (in absence of TiO2); (d) Aptamer-target complex (in presence of TiO2); and (e) Aptamer-TiO2 complex; (B) Fluorescence imaging of (i) FAM-aptamer; (ii) aptamer-TiO2; and (iii) aptamer-target complex (in presence of TiO2).

Mentions: UV spectral measurements were performed to characterize the interaction between aptamer and TiO2. Figure 2a, the absorption spectrum showed the characteristic absorption maxima of aptamer at 255 nm as shown in (curve b). Figure 2a strongly suggests that the TiO2 does not exhibit characteristics UV absorption at 255 nm (curve a). On addition of TiO2 (150 µg/mL), the UV absorbance of aptamer significantly enhance without change in peak position (curve e) at 255 nm. Thus, the obtained results emphasize the typical characteristic features of aptamer-TiO2 adsorption complex and electrostatic interaction [39]. In the presence of target molecule, the UV absorption decreases significantly (curve d), indicating target induced conformational changes in aptamer structure, which resist the aptamer to be adsorbed on TiO2 surface. The UV absorption of aptamer-target complex in the presence and absence of TiO2 showed similar type of pattern as shown in (curve c and d). Thus, the obtained results confirm that the fluorescence recovery was due to the formation of target-aptamer quadruplex, resulting increase in distance between FAM and TiO2. Additionally, the UV-Vis absorption results are summarized in Table S1.


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) UV absorption spectra of (a) TiO2; (b) Aptamer; (c) Aptamer-target complex (in absence of TiO2); (d) Aptamer-target complex (in presence of TiO2); and (e) Aptamer-TiO2 complex; (B) Fluorescence imaging of (i) FAM-aptamer; (ii) aptamer-TiO2; and (iii) aptamer-target complex (in presence of TiO2).
© Copyright Policy
Related In: Results  -  Collection

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

toxins-07-03771-f002: (A) UV absorption spectra of (a) TiO2; (b) Aptamer; (c) Aptamer-target complex (in absence of TiO2); (d) Aptamer-target complex (in presence of TiO2); and (e) Aptamer-TiO2 complex; (B) Fluorescence imaging of (i) FAM-aptamer; (ii) aptamer-TiO2; and (iii) aptamer-target complex (in presence of TiO2).
Mentions: UV spectral measurements were performed to characterize the interaction between aptamer and TiO2. Figure 2a, the absorption spectrum showed the characteristic absorption maxima of aptamer at 255 nm as shown in (curve b). Figure 2a strongly suggests that the TiO2 does not exhibit characteristics UV absorption at 255 nm (curve a). On addition of TiO2 (150 µg/mL), the UV absorbance of aptamer significantly enhance without change in peak position (curve e) at 255 nm. Thus, the obtained results emphasize the typical characteristic features of aptamer-TiO2 adsorption complex and electrostatic interaction [39]. In the presence of target molecule, the UV absorption decreases significantly (curve d), indicating target induced conformational changes in aptamer structure, which resist the aptamer to be adsorbed on TiO2 surface. The UV absorption of aptamer-target complex in the presence and absence of TiO2 showed similar type of pattern as shown in (curve c and d). Thus, the obtained results confirm that the fluorescence recovery was due to the formation of target-aptamer quadruplex, resulting increase in distance between FAM and TiO2. Additionally, the UV-Vis absorption results are summarized in Table S1.

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