A Simple and Highly Sensitive Thymine Sensor for Mercury Ion Detection Based on Surface Enhanced Raman Spectroscopy and the Mechanism Study.

Hao Yang,Yexiang Tong,Jian Chen,Fangyan Xie,Ping-Ping Fang,Sui-Bo Ye,Li Gong,Weihong Zhang,Yu Fu

doi:10.3390/nano7070192

Abstract

Mercury ion (Hg2+) is recognized as one of the most toxic metal ions for the environment and for human health. Techniques utilized in the detection of Hg2+ are an important factor. Herein, a simple thymine was successfully employed as the surface enhanced Raman spectroscopy sensor for Hg2+ ion detection. The limit of detection (LOD) of the developed sensor is better than 0.1 nM (0.02 ppb). This sensor can also selectively distinguish Hg2+ ions over 7 types of alkali, heavy metal and transition-metal ions. Moreover, the LOD of the sensor can even achieve 1 ppb in practical application in the nature system, which is half the maximum allowable level (10 nM, 2 ppb) stipulated in the US Environmental Protection Agency standard. Further investigation of the thymine-Hg2+-thymine coordination mechanism provides a possible means of detecting other metal ions by replacing the metal ion-specific ligands. This work paves the way for the detection of toxic metal ions and environmental problems.

Highlights

Mercury ion (Hg2+) is one of the most toxic water pollutants, and are hazardous to the environment, and harmful for human health [1,2,3]
Among the methods developed for Hg2+ ion detection, surface-enhanced Raman spectroscopy (SERS) is a promising candidate due to its distinct advantages in terms of high sensitivity, non-invasiveness, non-labeling, and fingerprint-type [14,15,16]
The morphology and EDS line scan was measured by TecnaiTM G2 F30 (TEM) (FEI Co., Ltd., Hillsboro, OR, USA), operating at 300 kV

Summary

Introduction

Mercury ion (Hg2+) is one of the most toxic water pollutants, and are hazardous to the environment, and harmful for human health [1,2,3]. Several SERS methods have been developed for the Hg2+ ion detection based on molecular probes, such as DNA [17,18], protein [19,20], oligonucleotides [21,22] and fluorophores [23,24]. These molecular probes are very complicated and expensive [25].

Materials

Preparation of Au NRs

Characterization

Findings

Conclusions