Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (12): 3600.doi: 10.7503/cjcu20210471

• Analytical Chemistry • Previous Articles     Next Articles

An Enzyme-free and Label-free Fluorescent Probe for Detection of Microcystin-LR Based on Circular DNA-Silver Nanoclusters

YANG Xinjie1, LAI Yanqiong1, LI Qiuyang1, ZHANG Yanli1, WANG Hongbin1, PANG Pengfei1(), YANG Wenrong2   

  1. 1.National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials,Yunnan Minzu University,Kunming 650500,China
    2.School of Life and Environmental Sciences,Deakin University,Geelong 3217,Australia
  • Received:2021-07-05 Online:2021-12-10 Published:2021-10-08
  • Contact: PANG Pengfei E-mail:pfpang@ynni.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21565031);the Applied Basic Research Project of Yunnan Provincial Science and Technology Department, China(202001AT070012)

Abstract:

An enzyme-free and label-free fluorescence sensing method for detection of Microcystin-LR(MC-LR) was developed based on circular DNA-silver nanoclusters (circular DNA-AgNCs) fluorescent probe, which was prepared by using circular DNA as template. The circular DNA was composed of MC-LR aptamer(Apt) and aptamer complementary(cDNA), which can be used as DNA template to synthesize AgNCs. The morphology and optical properties of prepared circular DNA-AgNCs were characterized by transmission electron microscope(TEM), ultraviolet?visible spectroscopy(UV-Vis) and fluorescent spectroscopy(FL). The experimental results showed that the circular DNA is dissociated due to the high specificity and affinity between Apt of circular DNA and MC-LR in the presence of object MC-LR, resulting in the releasing of cDNA-AgNCs with an enhanced fluorescent intensity at 610 nm. Under the optimized experimental conditions, the linear range of circular DNA-AgNCs fluorescent probe for MC-LR determination is 0.005—500 μg/L with a detection limit of 1.7 ng/L(S/N=3). The developed fluorescent probe has the advantages of simple preparation, no labe-ling and high sensitivity, providing a simple, reliable and effective method for the determination of Microcystin-LR in practical environmental water samples.

Key words: Microcystin-LR, Circular DNA, Silver nanoclusters, Fluorescent probe

CLC Number: 

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