AUnano/Fe-MOF hybrid electrode for highly sensitive determination of trace As(III)

In this work, a hybrid of amino-containing Fe-based metal-organic frameworks decorated with gold nanoparticles (Au-nano/Fe-MOFs) has been successfully fabricated via a simple adsorption/reduction of AuCl4- on FeMOF. The well-distribution of Au-nano on the Fe-MOF surface was confirmed by scanning electron microscopy, X-ray photoelectron spectroscopy and the N-2-sorption characterization. Electrochemical impedance spectroscopy indicated that in the Au-nano/Fe-MOF composite facilitated the charge transfer. The Au-nano/ Fe-MOF modified glassy carbon electrode (Au-nano/Fe-MOF/GCE) exhibited a superior sensitive response to As(III) by square wave anodic stripping voltammetry (SWASV). Under the optimized conditions, the wide linear ranges of 0.02 ppb similar to 2 ppb and 2 ppb similar to 30 ppb for As(III) detection were achieved with high sensitivity of 4.708 mu A-ppb(-1). The detection limit (LOD) was found to be 0.0085 ppb (S/N >= 3). Furthermore, the proposed Au-nano/Fe-MOF/GCE was successfully employed for As(III) measurement in real water samples with excellent repeatability and selectivity.

Automated summary

A hybrid of amino-containing Fe-based metal-organic frameworks decorated with gold nanoparticles was successfully fabricated via a simple adsorption/reduction method. The composite showed good charge transfer properties and high sensitivity for As(III) detection, with excellent repeatability and selectivity in real water samples.