Two New Fluorogenic Aptasensors Based on Capped Mesoporous Silica Nanoparticles to Detect Ochratoxin A

• Published in: ChemistryOpen (Weinheim) Vol. 6; no. 5; pp. 653 - 659
• Main Authors: Ribes, Àngela, Santiago‐Felipe, Sara, Bernardos, Andrea, Marcos, M. Dolores, Pardo, Teresa, Sancenón, Félix, Martínez‐Máñez, Ramón, Aznar, Elena
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01-10-2017; John Wiley and Sons Inc
• Subjects: aptamers; Materials selection; mesoporous materials; Nanomaterials; Nanoparticles; nanostructures; ochratoxin A; Porous materials; Reproducibility; Scaffolds; Selectivity; Sensitivity analysis; sensors; Silica; Silicon dioxide; ochratoxin A; sensors; aptamers; nanostructures; mesoporous materials
• ISSN: 2191-1363; 2191-1363
• DOI: 10.1002/open.201700106

Aptamers have been used as recognition elements for several molecules due to their great affinity and selectivity. Additionally, mesoporous nanomaterials have demonstrated great potential in sensing applications. Based on these concepts, we report herein the use of two aptamer‐capped mesoporous silica materials for the selective detection of ochratoxin A (OTA). A specific aptamer for OTA was used to block the pores of rhodamine B‐loaded mesoporous silica nanoparticles. Two solids were prepared in which the aptamer capped the porous scaffolds by using a covalent or electrostatic approach. Whereas the prepared materials remained capped in water, dye delivery was selectively observed in the presence of OTA. The protocol showed excellent analytical performance in terms of sensitivity (limit of detection: 0.5–0.05 nm), reproducibility, and selectivity. Moreover, the aptasensors were tested for OTA detection in commercial foodstuff matrices, which demonstrated their potential applicability in real samples.
Pop the cap: Two new fluorogenic aptasensors based on capped mesoporous silica nanoparticles for the detection of ochratoxin A (OTA) are prepared. The presence of OTA induces displacement of the aptamer from the solid surface, opens the pores, and selectively releases dye (see figure). These new capped nanomaterials allow accurate determination of OTA in realistic wheat samples and may allow the development of a simple test for the detection of OTA in food samples.