Adsorbent Assisted in Situ Electrocatalysis: An Ultra-Sensitive Detection of As(III) in Water at Fe₃O₄ Nanosphere Densely Decorated with Au Nanoparticles

Abstract

Most gold nanoparticle-based electrodes have been utilized for the analysis of highly toxic As(III), while nano-Fe3O4 materials are currently attracting considerable interest as an adsorbent for the removal of As(III). However, the combination of gold nanoparticles with Fe3O4 nanoadsorbents for stripping voltammetry is, to the best of our knowledge, unexplored. Here, a sensing interface for ultrasensitive detection of As(III) is designed and constructed by abundantly dispersing Au nanoparticles (Au NPs) on the surface of the Fe3O4 nanosphere. The Au@Fe3O4 nanospheres are covered by the room temperature ionic liquid (RTIL) and then modified on the screen-printed carbon electrode (SPCE). By combining the excellent catalytic properties of the Au nanoparticles (∼3-9 nm in diameter) with the good adsorption capacity of Fe3O4 nanospheres toward As(III), as well as the good conductivity of RTIL, the Au@Fe3O4-RTIL shows excellent performance in the detection of arsenic under nearly neutral conditions without modifying the morphology of the sensing interface. Through optimization of the experimental conditions, an ultrahigh sensitivity of 458.66 μA ppb(-1) cm(-2) from 0.1 to 1 ppb with a detection limit (3σ method) of 0.0022 ppb was obtained. The reproducibility and reliability of the Au@Fe3O4-RTIL sensing interface was also evaluated with good results. Finally, we used this platform to analyze real samples.

Highly Sensitive and Selective Detection of Arsenic Using Electrogenerated Nanotextured Gold Assemblage

“…During the forward potential sweep, the characteristic peak of As 0 oxidation to As 3+ is observed at 0.25 V Ag/AgCl , matching well with the literature values. 36,45 This current is then followed by a large reduction peak during reverse sweep because of As deposition (Figure 3a). However, no such redox behavior is observed in the arsenic-free electrolyte solution on Au/GNE.…”

Electrochemical Detection of Nitrite in Food Based on Poly (3,4-ethylenedioxythiophene) Doped with Fe3O4 Nanoparticles Loaded Carboxylated Nanocrystalline Cellulose

“…The XRD patterns of CNCC and Fe 3 O 4 -CNCC composite are shown in Fig S2. The diffraction peaks at 2θ = 16.5°, 22.5° and 34.5° (labeled by the star) correspond to (110), (200) and (004) planes of CNCC respectively. 39 In the case of CNCC-Fe 3 O 4 composite, the emerging diffraction peaks were from the (022), (400), (333) and (044) crystallographic planes of cubic structure of Fe 3 O 4 , 25 indicating that Fe 3 O 4 has been successfully modified on CNCC.…”

“…24 Fe 3 O 4 nanosphere decorated with Au nanoparticles was used as a kind of catalyst for the detection of As(III) in water. 25 However, Fe 3 O 4 nanoparticles are thermodynamically unstable and tend to aggregate to form bulk particle. To overcome this problem, Fe 3 O 4 -CNCC was synthesized by dispersing Fe 3 O 4 nanoparticles on the surface of CNCC in this work.…”

Recent Progresses in Nanobiosensing for Food Safety Analysis

“…A reporter nanomaterial is a nanomaterial that can be used as electrochemical, colorimetric, fluorescent, or other types of signal molecule. Metal NPs [ 29 ], metallic oxide NPs [ 30 , 31 ] and QDs [ 32 , 33 ] are known to function as electrochemical reporter (stripping voltammetry). On the other hand, metal nanoclusters [ 34 , 35 ], QDs [ 36 , 37 ] and up-conversion NPs [ 38 ] can emit fluorescence that can influenced by quencher, change in structure or environment [ 39 ].…”