Chem. J. Chinese Universities ›› 2025, Vol. 46 ›› Issue (5): 20250008.doi: 10.7503/cjcu20250008

• Articles:Analytical Chemistry • Previous Articles     Next Articles

Fluorescent Probe for Detection of Microcystin-LR Based on Poly(thymidine)-Copper Nanoclusters and Aptamer-Gold Nanoparticles

MENG Hua1, A Huaying1, LUO Pingxin1, ZHANG Yanli1(), GAO Lianxun1, WANG Hongbin1, YANG Wenrong1,2, PANG Pengfei1()   

  1. 1.Functional Nanomaterial?based Chemical and Biological Sensing Technology Innovation Team of Department of Education of Yunnan Province,Yunnan Minzu University,Kunming 650504,China
    2.School of Life and Environmental Sciences,Deakin University,Geelong 3217,Australia
  • Received:2025-01-08 Online:2025-05-10 Published:2025-03-05
  • Contact: ZHANG Yanli E-mail:ylzhang@ymu.edu.cn;pfpang@aliyun.com
  • Supported by:
    the National Natural Science Foundation of China(21565031);the Basic Research Project of Yunnan Provincial Science and Technology Department, China(202001AT070012);the Graduate Research Innovation Project of Yunnan Minzu University, China(2024SKY135)

Abstract:

A fluorescent probe of poly(thymidine)-copper nanoclusters/aptamer-gold nanoparticles(poly(T)-CuNCs/aptamer-AuNPs) was constructed for highly sensitive sensing detection of microcystin-LR(MC-LR) using DNA template method. Three DNA nucleotides were designed, including MC-LR aptamer, and two poly(thymidine) ssDNA(poly(T) S1 and poly(T) S2). Using poly(T) S1 and poly(T) S2 as templates, poly(T) S1-CuNCs and poly(T) S2-CuNCs with pink fluorescence were synthesized by reducting Cu2+ with ascorbic acid(AA). Aptamer labeled with thiol groups at two both ends were linked with AuNPs through Au—S bonds to form AuNPs-aptamer- AuNPs bioconjugates. AuNPs-aptamer-AuNPs hybridized with poly(T)-CuNCs to form dsDNA-CuNCs. Fluorescence resonance energy transfer(FRET) occurred between CuNCs and AuNPs in the dsDNA-CuNCs structure, leading to fluorescence quenching of dsDNA-CuNCs. In the presence of target MC-LR, MC-LR specifically bonded with aptamer in dsDNA-CuNCs, resulting in the dissociation of dsDNA structure. The poly(T)-CuNCs were released into the solution, restoring the system's fluorescence. An "off-on" type of fluorescent probe was constructed for the detection of MC-LR. The linear range for MC-LR detection is 1 ng/L—500 µg/L, with a detection limit of 0.3 ng/L (S/N=3). The proposed fluorescent aptamer probe possesses the advantages of simple preparation, high selectivity, and can be applied for quantitative detection and analysis of MC-LR in real water samples.

Key words: Microcystin-LR, Poly(thymine)-copper nanoclusters, Aptamer-gold nanoparticles, Fluorescent probe

CLC Number: 

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