Work

Electrochemical Sensing of Lead Ions Using Ionophore-Modified Raspberry-like Fe3O4–Au Nanostructures via Differential Pulse Voltammetry

Year: 2025

Type: article

Abstract: This study presents the design and application of an electrochemical sensor for selective detection of lead ions (Pb2+) based on ionophore-modified raspberry-like Fe3O4–Au nanostructures. The material was engineered with a magnetic Fe3O4 core, coated with polyethyleneimine (PEI) to facilitate nucleation, and subsequently decorated with Au nanoparticles, providing a raspberry-like (Fe3O4@PEI@AuNPs) nanostructure with high surface area and excellent electrochemical conductivity. Surface functionalization with Lead Ionophore IV (ionophore thiol) introduced Pb2+-selective binding sites, whose presence and structural evolution were verified by TEM and Raman spectroscopy. The Fe3O4 core endowed strong magnetic properties, enabling facile manipulation and immobilization onto screen-printed carbon electrodes (SPCEs) via physical adsorption, while the Au nanoparticles enhanced electron transfer, supplied thiol-binding sites for stable ionophore anchoring, and increased the effective electroactive surface area. Operational conditions were systematically optimized, with acetate buffer (HAc/NaAc, pH 5.7) and chronoamperometric preconcentration (CA) at −1.0 V for 175 s identified as optimal for differential pulse voltammetry (DPV) measurements. Under these conditions, the sensor exhibited a linear response toward Pb2+ from 0.025 mM to 2.00 mM with superior sensitivity and reproducibility compared to conventional AuNP-modified SPCEs. Furthermore, the ionophore-modified Fe3O4–Au nanostructure-based sensor demonstrated outstanding selectivity for Pb2+ over competing heavy metal ions (Cd2+, Hg2+, Cr3+), owing to the specific coordination interaction of Lead Ionophore IV with target ions. These findings highlight the potential of raspberry-like Fe3O4@PEI@AuNP nanostructures as a robust and efficient electrochemical platform for the sensitive and selective detection of toxic heavy metal ions.

Source: Polymers

DOI: 10.3390/polym17223015

Authors: Giang Huong Dau, Tin Phan Nguy, Tram Thi Ngoc Do, Thanh Van Pham, Lien Thi Ngoc Truong

Institutions: Viện Khoa học và Công nghệ Việt Nam - Hàn Quốc, Trường Đại học Khoa học và Công nghệ Hà Nội, Hanoi University of Science and Technology, Vietnam National University, Hanoi, VNU University of Science

Language: English

Topic: Electrochemical Analysis and Applications

Subfield: Electrochemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $3,258

Funder: Ministry of Science and Technology