title: A self-assembly aptasensor based on thick-shell quantum dots for sensing of ochratoxin A.
abstract: A novel self-assembling aptasensor was fabricated by precisely attaching three phosphorothioate-modified capture aptamers onto a single thick-shell quantum dot in a controllable manner for monitoring of ochratoxin A (OTA), a poisonous contaminant widespread in foodstuffs. Herein, CdSe/CdS QDs coated in ten layer CdS shells were synthesized using a continual precursor injection method. Analysis of the prepared CdSe/CdS QDs showed a zinc-blende structure, high photoluminescence quantum yields (>80%), and a photoemission peak with a narrow full-width at half-maximum (about 29 nm), all qualities that render them as a superior choice for optical applications. By adjusting the number of phosphorothioate bases in the anchor domain, the tunable-valency aptasensor was able to self-assemble. In the sensing strategy, the thick-shell quantum dot was provided as an acceptor while OTA itself was used as a donor. In the presence of OTA, the capture aptamers drive the aptasensor function into a measurable signal through a fluorescence resonance energy transfer (FRET) system. The newly developed aptasensor had a detection limit as low as 0.5 ng mL(-1), with a linear concentration in the range of 1 to 30 ng mL(-1), and therefore meets the requirements for rapid, effective, and anti-interference sensors for real-world applications. Moreover, the high quality thick-shell QDs provide an ideal alternative for highly sensitive imaging and intensive illumination in the fields of biotechnology and bioengineering.
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Xianfeng
authors: X
authors: Chu
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Xiaowen
authors: X
authors: Dou
authors: State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors: Ruizheng
authors: R
authors: Liang
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Menghua
authors: M
authors: Li
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Weijun
authors: W
authors: Kong
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Xihui
authors: X
authors: Yang
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com.
authors: Jiaoyang
authors: J
authors: Luo
authors: Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100193, China. yangmeihua15@hotmail.com and Institute of Hainan Branch of Medicinal Plant Development, Chinese Academy of Medical Sciences & Peking Union Medical College, Wanning 571533, China.
authors: Meihua
authors: M
authors: Yang
authors: School of Pharmacy, Jiangsu University, Zhenjiang 212013, China.
authors: Ming
authors: M
authors: Zhao
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques; D019187:Cadmium Compounds / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D057230:Limit of Detection; D009793:Ochratoxins / Q000032:analysis*; D045663:Quantum Dots / Q000737:chemistry*; D018036:Selenium Compounds / Q000737:chemistry; D013440:Sulfides / Q000737:chemistry
chemical_list: D052157:Aptamers, Nucleotide; D019187:Cadmium Compounds; D009793:Ochratoxins; D018036:Selenium Compounds; D013440:Sulfides; C034939:cadmium sulfide; C025589:ochratoxin A; C058667:cadmium selenide