Gold-core silver-shell nanoparticles modified magnetic-based metal-organic frameworks for dopamine sensing electrodes: Magnetic Fe-based and LSPR gain mechanisms
Journal
Journal of Alloys and Compounds
Journal Volume
1065
Start Page
188120
ISSN
0925-8388
Date Issued
2026-05
Author(s)
Abstract
This study modifies porous iron-based metal-organic frameworks (MOFs, MIL-101(Fe)) with gold-core silver-shell nanoparticles (Au@Ag NPs) for dopamine sensing electrodes. The electrode fabrication process consists of three sections: (i) use the solvothermal method to synthesize the optimal MIL-101(Fe) structure using ferric chloride and terephthalic acid at different ratios of 1:1, 2:1, and 4:1; (ii) by chemical synthesis, prepare Au, Ag, and Au@Ag NPs; (iii) uniformly dope the Au, Ag, and Au@Ag NPs onto the MIL-101(Fe) sensing window. Electrochemical analysis of their redox reaction characteristics is conducted, and optimal sensitivity, linearity, and fit superiority are determined. Experimental results show that the sensing electrode has two important gain mechanisms. First, the magnetic Fe group exhibits excellent electron exchange with dopamine. The optimal synthesis ratio of ferric chloride to terephthalic acid in MIL-101(Fe) is 2:1. Secondly, the local surface plasmon resonance (LSPR) properties of the noble metal NPs effectively enhance electrode sensitivity, linearity, and reduce resistance. The sensing current, of the unmodified MIL-101(Fe) electrode, when measured by cyclic voltammetry (CV), is 80 μA, whereas the electrodes modified by Ag, Au, and Au@Ag NPs increase to 100, 125, and 175 μA, respectively. Furthermore, the sensing current of the modified electrode increases from 40 μA, to 90, 100, and 120 μA measured by chronoamperometry (CA). The Rct resistance values, measured by electrochemical impedance spectroscopy (EIS), decrease from 637.2 to 380.6, 310, and 195.2 Ω, respectively. The Au@Ag@MIL-101(Fe) sensing electrode maintains over 93% efficiency after 7 days in lifetime testing, and good anti-interference performance. © 2026
Subjects
Core-shell nanoparticles (Au@Ag NPs)
Current sensors
Gold nanoparticles (Au NPs)
Local surface plasmon resonance (LSPR)
Metal organic frameworks (MOFs)
Silver nanoparticles (Ag NPs)
Publisher
Elsevier BV
Type
journal article