Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (8): 20220202.doi: 10.7503/cjcu20220202

• Analytical Chemistry • Previous Articles     Next Articles

A Ratiometric Electrochemical Sensor Based on Silver Ion Interaction with DNA for the Detection of Silver Ion

LI Yulong, XIE Fating, GUAN Yan, LIU Jiali, ZHANG Guiqun, YAO Chao, YANG Tong(), YANG Yunhui(), HU Rong()   

  1. School of Chemistry and Chemical Engineering,Yunnan Normal University,Kunming 650500,China
  • Received:2022-04-01 Online:2022-08-10 Published:2022-04-30
  • Contact: YANG Tong,YANG Yunhui,HU Rong E-mail:yt09132149@163.com;yyhui2002@aliyun.com;hudierong_168@163.com
  • Supported by:
    the National Natural Science Foundation of China(21864026)

Abstract:

A ratiometric electrochemical sensor for detecting silver ion(Ag+) is proposed. Single-stranded DNA labeled with chromium metal organic framework(Cr-MIL-101 NH2) is used as a signal probe(Cr-MOFs-SP), and ferrocene formic acid in the electrolyte solution is used as an internal reference probe(Fc-RP). In the presence of Ag+, the signal of Cr-MOFs can be detected. At the same time, the signal of ferrocene formic acid remained stable. Therefore, the Ag+ concentration can be monitored by the ratiometric response of ICr-MOFs-SP/IFc-RP. The proposed ratiometric biosensor can effectively eliminate the influence of the external environment and avoid electrochemical background signals, also improve the reproducibility, accuracy and sensitivity of detection. The DNA tetrahedral nanomaterials(NTH) with a three-dimensional structure can effectively eliminate the non-specific adsorption of DNA. The well-designed DNA NTH enhances mechanical rigidity, can increase the capture amount of Ag+ and the load of signal substances, and further improve the detection sensitivity. This ratiometric biosensor has a good selectivity for Ag+ detection, a wide linear range(0.1—100 nmol/L) and a low detection limit(33 pmol/L). This sensor has been used for the determination of Ag+ content in Dianchi Lake water samples with the recovery rate of 96.8%—103.0%, which shows that this sensor has potential practical application prospects.

Key words: Silver ion, Electrochemical sensor, Ratiometric type, Tetrahedron, Metal organic framework material

CLC Number: 

TrendMD: