A FRET-based aptasensor for ochratoxin A detection using graphitic carbon nitride quantum dots and CoOOH nanosheets as donor-acceptor pair

• Published in: Talanta (Oxford) Vol. 218; p. 121159
• Main Authors: Bi, Xiaoya, Luo, Lijun, Li, Libo, Liu, Xiaohong, Chen, Bainian, You, Tianyan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01-10-2020
• Subjects: Cobalt; Cobalt oxyhydroxide nanosheets; Fluorescence Resonance Energy Transfer; Förster resonance energy transfer; Graphite; Graphitic carbon nitride quantum dots; Nitrogen Compounds; Ochratoxin A; Ochratoxins; Oxides; Quantum Dots; Förster resonance energy transfer; Ochratoxin A; Graphitic carbon nitride quantum dots; Cobalt oxyhydroxide nanosheets
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2020.121159

A new fluorescence aptasensor for Ochratoxin A (OTA) analysis in corn and barley flour was developed owing to the favourable quenching function of cobalt oxyhydroxide (CoOOH) nanosheets. The first combination of graphitic carbon nitride quantum dots (g-CNQDs) and CoOOH nanosheets as efficient energy donor-acceptor pair was reported, and the quenching mechanism was proved by investigating the fluorescence lifetime of g-CNQDs. The aptamer-modified g-CNQDs (g-CNQDs-apt) were adsorbed onto CoOOH nanosheets surface by van der Waals force. Consequently, the Förster resonance energy transfer (FRET) from g-CNQDs-apt to CoOOH nanosheets was initiated, leading to quenched fluorescence. With the addition of OTA, the linear aptamer specifically bound with OTA to form G-quadruplex, which had relatively weak interaction with the CoOOH nanosheets and separated from the nanosheets surface. Thus, the FRET process between g-CNQDs-apt and CoOOH nanosheets was hindered, leading to the fluorescence of g-CNQDs-apt recovered clearly. The developed aptasensor exhibited acceptable detection limit with 0.5 nM and desirable linear relationship from 1 nM to 140 nM. Meanwhile, the aptasensor possessed multiple advantages, including easy operation, rapid detection and high selectivity. Moreover, the aptamer sensing platform was favorably applied for OTA determination in cereal (barley and corn flour), in which the recoveries varied from 94.5% to 101% with the relative standard deviation under 2.24%.
A fluorescence aptasensor based on Förster resonance energy transfer between graphitic carbon nitride quantum dots and CoOOH nanosheets for selective detection of Ochratoxin A was developed. [Display omitted]
•The CoOOH was firstly used as acceptor for g-CNQDs to develop FRET system.•A novel fluoresence aptasensor was designed for selective detection of OTA.•The aptasensor showed excellent analysis performance for detecting OTA.•The aptasensor was successfully applied in the corn and barley flour.