Graphene quantum dots anchored onto mercaptopyridine-substituted zinc phthalocyanine-Au@Ag nanoparticle hybrid: Application as fluorescence “off-on-off” sensor for Hg2+ and biothiols

Ojodomo J. Achadu, Tebello Nyokong

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

Novel supramolecular hybrid containing polyethyleneimine-functionalized graphene quantum dots (PEI-GQDs) and mercaptopyridine-substituted zinc phthalocyanine (Pc)-Au@Ag nano-alloys is presented in this study. The designed hybrid was employed as a dual fluorescence nanoprobe for Hg2+ and biothiol detection in aqueous solution using PEI-GQDs as the fluorescence switching signal probe. The dual sensing platform for the analytes detection is firstly, based on the quenching (turn “OFF”) of the PEI-GQDs fluorescence upon π-π interaction or electrostatic attraction with Pc-Au@Ag conjugate. The quenched fluorescence can be switched back to the “ON” mode in the presence of Hg2+ and switched “OFF” again when biothiols are introduced to capture the Hg2+ ion via the formation of the strong metal-thiol bond (Hg-S). The “off-on-off” processes were modulated by different amounts of Hg2+ and biothiols. The nanoprobes were found to be highly stable and selective towards the target analytes in the presence of other amino acids and metal ions. Also, the probes were successfully deployed in the assay of the test analytes in spiked samples.

Original languageEnglish
Pages (from-to)189-201
Number of pages13
JournalDyes and Pigments
Volume145
DOIs
Publication statusPublished - 3 Jun 2017
Externally publishedYes

Bibliographical note

Funding Information:
This work was supported by the Department of Science and Technology and National Research Foundation, South Africa through DST/NRF South African Research Chairs Initiative for Professor of Medicinal Chemistry and Nanotechnology (UID 62620) as well as Rhodes University/DST Centre for Nanotechnology Innovation, Rhodes University, South Africa.

Publisher Copyright:
© 2017 Elsevier Ltd

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