title: Functionalized gold nanoparticles/reduced graphene oxide nanocomposites for ultrasensitive electrochemical sensing of mercury ions based on thymine-mercury-thymine structure.
abstract: A sensitive, selective and reusable electrochemical biosensor for the determination of mercury ions (Hg(2+)) has been developed based on thymine (T) modified gold nanoparticles/reduced graphene oxide (AuNPs/rGO) nanocomposites. Graphene oxide (GO) was electrochemically reduced on a glassy carbon substrate. Subsequently, AuNPs were deposited onto the surface of rGO by cyclic voltammetry. For functionalization of the electrode, the carboxylic group of the thymine-1-acetic acid was covalently coupled with the amine group of the cysteamine which self-assembled onto AuNPs. The structural features of the T bases functionalized AuNPs/rGO electrode were confirmed by attenuated total reflection infrared (ATR-IR) spectroscopy and scanning electron microscopy (SEM) spectroscopy. Each step of the modification process was characterized by cyclic voltammetry (CV) and electrochemical impedence spectroscopy (EIS). The T bases modified AuNPs/rGO electrode was applied to detect various trace metal ions by differential pulse voltammetry (DPV). The proposed biosensor was found to be highly sensitive to Hg(2+) in the range of 10 ng/L-1.0 µg/L. The biosensor afforded excellent selectivity for Hg(2+) against other heavy metal ions such as Zn(2+), Cd(2+), Pb(2+), Cu(2+), Ni(2+), and Co(2+). Furthermore, the developed sensor exhibited a high reusability through a simple washing. In addition, the prepared biosensor was successfully applied to assay Hg(2+) in real environmental samples.
authors.affiliation: Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. Electronic address: mlin@sdu.edu.cn.
authors.forename: Meng
authors.initials: M
authors.lastname: Lin
authors.affiliation: Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
authors.forename: Hongxiu
authors.initials: H
authors.lastname: Dai
authors.affiliation: Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China. Electronic address: hyma@sdu.edu.cn.
authors.forename: Houyi
authors.initials: H
authors.lastname: Ma
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D006108:Graphite / Q000737:chemistry; D008628:Mercury / Q000737:chemistry / Q000302:isolation & purification*; D053768:Metal Nanoparticles / Q000737:chemistry*; D053761:Nanocomposites / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D013941:Thymine / Q000737:chemistry
chemical_list: D010087:Oxides; D006046:Gold; D006108:Graphite; D008628:Mercury; D013941:Thymine
keywords: Electrochemical sensor; Gold nanoparticles; Mercury ion; Reduced graphene oxide; Thymine–Hg(2+)–Thymine