title: Magnetic-fluorescent-targeting multifunctional aptasensorfor highly sensitive and one-step rapid detection of ochratoxin A.
abstract: A multifunctional aptasensor for highly sensitive and one-step rapid detection of ochratoxin A (OTA), has been developed using aptamer-conjugated magnetic beads (MBs) as the recognition and concentration element and a heavy CdTe quantum dots (QDs) as the label. Initially, the thiolated aptamer was conjugated on the Fe3O4@Au MBs through Au-S covalent binding. Subsequently, multiple CdTe QDs were loaded both in and on a versatile SiO2 nanocarrier to produce a large amplification factor of hybrid fluorescent nanoparticles (HFNPs) labeled complementary DNA (cDNA). The magnetic-fluorescent-targeting multifunctional aptasensor was thus fabricated by immobilizing the HFNPs onto MBs' surface through the hybrid reaction between the aptamer and cDNA. This aptasensor can be produced at large scale in a single run, and then can be conveniently used for rapid detection of OTA through a one-step incubation procedure. The presence of OTA would trigger aptamer-OTA binding, resulting in the partial release of the HFNPs into bulk solution. After a simple magnetic separation, the supernatant liquid of the above solution contained a great number of CdTe QDs produced an intense fluorescence emission. Under the optimal conditions, the fluorescence intensity of the released HFNPs was proportional to the concentration of OTA in a wide range of 15 pg mL(-1) -100 ng mL(-1) with a detection limit of 5.4 pg mL(-1) (S/N=3). This multifunctional aptasensor represents a promising path toward routine quality control of food safety, and also creates the opportunity to develop aptasensors for other targets using this strategy.
authors: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China; Changzhou College of Information Technology, Changzhou 213164, PR China.
authors: Chengquan
authors: C
authors: Wang
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Jing
authors: J
authors: Qian
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Kan
authors: K
authors: Wang
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: wangkun@ujs.edu.cn.
authors: Kun
authors: K
authors: Wang
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Qian
authors: Q
authors: Liu
authors: Key Laboratory of Modern Agriculture Equipment and Technology, School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Xiaoya
authors: X
authors: Dong
authors: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China.
authors: Chengke
authors: C
authors: Wang
authors: School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China. Electronic address: h_xingyi@163.com.
authors: Xingyi
authors: X
authors: Huang
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000737:chemistry; D018076:DNA, Complementary / Q000737:chemistry; D005504:Food Analysis; D006801:Humans; D057230:Limit of Detection; D060328:Magnetic Phenomena; D009793:Ochratoxins / Q000737:chemistry / Q000302:isolation & purification*; D045663:Quantum Dots / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013691:Tellurium / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D018076:DNA, Complementary; D009793:Ochratoxins; C025589:ochratoxin A; D012822:Silicon Dioxide; D013691:Tellurium; C028337:cadmium telluride
keywords: Aptasensor; Multifunctional; Ochratoxin A; Rapid detection; Signal amplification