title: A FRET-based ratiometric fluorescent aptasensor for rapid and onsite visual detection of ochratoxin A.
abstract: A color change observable by the naked eye to indicate the content of an analyte is considered to be the most conceivable way of various sensing protocols. By taking advantage of the Förster resonance energy transfer (FRET) principles, we herein designed a dual-emission ratiometric fluorescent aptasensor for ochratoxin A (OTA) detection via a dual mode of fluorescent sensing and onsite visual screening. Amino group-modified OTA's aptamer was firstly labeled with the green-emitting CdTe quantum dots (gQDs) donor. The red-emitting CdTe QDs (rQDs) which were wrapped in the silica sphere could serve as the reference signal, while the gold nanoparticle (AuNP) acceptors were attached on the silica surface to bind with the thiolated complementary DNA (cDNA). The hybridization reaction between the aptamer and the cDNA brought gQD-AuNP pair close enough, thereby making the FRET occur in the aptasensor fabrication, while the subsequent fluorescence recovery induced by OTA was obtained in the detection procedure. Based on the red background of the wrapped rQDs, the aptasensor in response to increasing OTA displayed a distinguishable color change from red to yellow-green, which could be conveniently readout in solution even by the naked eye. Since the bioconjugations used as the aptasensor can be produced at large scale, this method can be used for in situ, rapid, or high-throughput OTA detection after only an incubation step in a homogeneous mode. We believe that this novel aptasensing strategy provides not only a promising method for OTA detection but also a universal model for detecting diverse targets by changing the corresponding aptamer.
authors.affiliation: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, P. R. China. wangkun@ujs.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Qian
authors.forename: Kan
authors.initials: K
authors.lastname: Wang
authors.forename: Chengquan
authors.initials: C
authors.lastname: Wang
authors.forename: Mengjuan
authors.initials: M
authors.lastname: Hua
authors.forename: Zhenting
authors.initials: Z
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Hanping
authors.initials: H
authors.lastname: Mao
authors.forename: Kun
authors.initials: K
authors.lastname: Wang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D019187:Cadmium Compounds / Q000737:chemistry; D003116:Color; D003124:Colorimetry / Q000295:instrumentation* / Q000379:methods; D018076:DNA, Complementary / Q000378:metabolism; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods; D005456:Fluorescent Dyes / Q000737:chemistry*; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination; D006046:Gold / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D046529:Microscopy, Electron, Transmission; D009693:Nucleic Acid Hybridization; D009793:Ochratoxins / Q000032:analysis*; D045663:Quantum Dots; D015203:Reproducibility of Results; D012822:Silicon Dioxide / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013691:Tellurium / Q000737:chemistry; D014920:Wine / Q000032:analysis
chemical_list: D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D018076:DNA, Complementary; D005456:Fluorescent Dyes; D009793:Ochratoxins; C025589:ochratoxin A; D006046:Gold; D012822:Silicon Dioxide; D013691:Tellurium; C028337:cadmium telluride