ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Introducing a nanozyme-based sensor for selective and sensitive detection of mercury(II) using its inhibiting effect on production of an indamine polymer through a stable n-electron irreversible system

Morteza Akhond, Saeed Reza Hormozi Jangi, Sedigheh Barzegar, and Ghodratollah Absalan

Professor Massoumi Laboratory, Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran

E-mail: akhond@shirazu.ac.ir

Received: 12 July 2019  Accepted: 25 October 2019

Abstract:

A sensitive and selective nanozyme-based sensor for Hg²⁺ detection has been constructed by utilizing a stable n-electron irreversible system using 3,3′-diaminobenzidine (DAB) for producing an indamine polymer as the analytical probe. In this system, oxidation of DAB to indamine polymer by hydrogen peroxide was catalyzed using gold nanozyme. In the presence of Hg²⁺, production of the indamine polymer was inhibited and consequently the corresponding change in absorbance measured at 460 nm was linearly related to the concentration of Hg²⁺. The method showed good selectivity toward Hg²⁺ against its coexisting species and a linear working range of 0.14–7.35 mg L⁻¹ with a detection limit of 20 µg L⁻¹ was achieved for Hg²⁺ measurement. The method is appropriate for the analysis of Hg²⁺ in water samples.

Graphic Abstract:

Keywords: 3,3′-Diaminobenzidine; Nanozyme; Colorimetry; Peroxidase; Mercury(II); Hydrogen peroxide

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-019-00981-w

Chemical Papers 74 (4) 1321–1330 (2020)