Sensing of mercury and silver ions using branched Au nanoparticles prepared by hyperbranched polyethylenimine fabricated and capped AuNPs seeds

Yuxi Li; Jie Bian; Tao Lin; Yiyun Zhang; Xunyong Liu; Yi Liu

doi:10.1088/1361-6528/ac05eb

Sensing of mercury and silver ions using branched Au nanoparticles prepared by hyperbranched polyethylenimine fabricated and capped AuNPs seeds

Nanotechnology. 2021 Jun 21;32(37). doi: 10.1088/1361-6528/ac05eb.

Authors

Yuxi Li¹, Jie Bian¹, Tao Lin¹, Yiyun Zhang¹, Xunyong Liu¹, Yi Liu¹

Affiliation

¹ School of Chemistry and Materials Science, Ludong University, Yantai 264001, People's Republic of China.

PMID: 34044377
DOI: 10.1088/1361-6528/ac05eb

Abstract

Branched AuNPs usually have two or more local surface plasmon resonance (LSPR) absorption bands due to their structural anisotropy, and the LSPR performance is more sensitive to the changes of environmental refractive index than that of spherical AuNPs. The design and preparation of branched AuNPs as colorimetric probes is expected to improve the selectivity and sensitivity of detection of targets. In this paper, branched AuNPs were innovatively synthesized via hyperbranched polyethylenimine (HPEI) fabricated and capped AuNPs as seeds and cetyltrimethylammonium bromide (CTAB) as template agent. The branched AuNPs were characterized by TEM, DLS, zeta potentials and UV-vis spectra. Using the branched AuNPs as a colorimetric probe, the detection system for Hg²⁺and Ag⁺showed bright color changes from blue to orange and blue to green based on the morphological evolution of branched AuNPs. The branched AuNPs could selectively detect Hg²⁺and Ag⁺at concentrations as low as 77 and 140 nM, respectively. Moreover, this unusual colorimetric method has been successfully used in real water samples and has great potential as a simple, rapid, sensitive and selective method for the detection of Hg²⁺and Ag⁺.

Keywords: AuNPs; LSPR; colorimetric detection; hyperbranched polyethylenimine.