Electrochemiluminescence Detection of Silver Ion Based on Trigeminal Structure of DNA

Zhejian Li,Xuemei Fan,Baoyue Cao,Fei Yuan,Shumin Wang,Fengying Chen

doi:10.21577/0103-5053.20190017

Zhejian Li, Xuemei Fan + Show 4 more

Open Access

https://doi.org/10.21577/0103-5053.20190017

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Abstract

A novel electrochemiluminescence (ECL) biosensor for highly sensitive and selective detection of Ag+ is developed based on the sensitive “turn-on” structure-switching trigeminal structure of deoxyribonucleic acid (DNA-TS). DNA-TS consists of three oligonucleotides hybridized to form three double-stranded DNA like Y-shaped DNA structure. The formation of DNA-TS makes the ECL sign Ru(bpy)2(mcbpy-O-Su-ester)(PF6)2 of reporter probe approach to the electrode surface and thus increase the ECL signal intensity. The “signal-on” ECL biosensor could detect Ag+ concentration in the range from 1.0 × 10-11 to 3.2 × 10-9 mol L-1, and the limit of detection is 3.0 × 10-12 mol L-1. The strategy is sensitive and rapid. This approach could be extended to the design of sensors for other desired heavy metal ions as well. Such ECL sensors are promising for sensitive detection of other heavy metal ions.

Highlights

As one of the trace elements in the human body, silver ions (Ag+) are harmless in trace amounts
P2 and P3 to form a trigeminal structure of deoxyribonucleic acid (DNA), which makes the ECL sign Ru1 of reporter probe approach to the electrode surface and increase the ECL signal intensity
The reporter probe was characterized by UV-Vis absorption spectrophotometry and the fluorescence imaging

Summary

Introduction

As one of the trace elements in the human body, silver ions (Ag+) are harmless in trace amounts. P2 and P3 to form a trigeminal structure of DNA, which makes the ECL sign Ru1 of reporter probe approach to the electrode surface and increase the ECL signal intensity. This method for the detection of Ag+ is precise, sensitive, fast, easy and high selective. 6.0 μL of mixture solution containing 1.0 μmol L-1 of reporter probe, 1 μmol L-1 of auxiliary probe and different concentrations of Ag+, was dropped onto the biosensor and incubated for 35 min, followed by 3 washes with the washing buffer. ECL detection and electrochemical impedance spectroscopy (EIS) measurements were both conducted in saturated and still air at ambient temperature

Results and Discussion

Method

Conclusions