Electrochemical aptasensor based on Au@HS-rGO and thymine-Hg²⁺-thymine structure for sensitive detection of mercury ion

Key Words:Hydraulic structures;DNA - Glass membrane electrodes - Mercury (metal) - Voltammetry

Abstract:A sensitive electrochemical aptasensor was prepared on the basis of gold modified thiol reduced graphene (Au@HS-rGO) and thymine-Hg²⁺-thymine (T-Hg²⁺-T) constitution for the checkout of Hg²⁺. Firstly, Au@HS-rGO was fabricated as the substrate onto the glassy carbon electrode (GCE) surface, which facilitated the subsequent introduction of single-stranded DNA onto the electrode. Following that, thionine (Th) was immobilized on the electrode surface depend on the physical size effect of T and Hg²⁺. Finally, the amount of Hg²⁺ was determined by differential pulse voltammetry (DPV) of Th. Under the best conditions, the linear range of the aptasensor to Hg²⁺ was in the range of 1–200 nmol/L and the detection limit was as low as 0.38 nmol/L. Simultaneously, good selectivity and acceptable reproducibility were revealed in the designed aptasensor. Moreover, the design thought may provide an idea for the detection of other substances in the water sample.<br/> © 2019 Elsevier B.V.

Volume:848

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Translation or Not:no