An Electrochemical Sensor for H₂O₂ Based on Au Nanoparticles Embedded in UiO-66 Metal–Organic Framework Films

Abstract

Precise and real-time detection of hydrogen peroxide (H2O2) is particularly necessary in pharmaceutical, industrial, and military applications because of the strong oxidability of H2O2. Here, an electrocatalytic active film with Au nanoparticles (Au NPs) embedded in a metal–organic framework (UiO-66) film was in situ prepared on the surface of an electrode for H2O2 detection. The size of Au nanoparticles and electrochemical activity of the Au nanoparticles/UiO-66 film could be controlled by manipulating the electrodeposition conditions. Since Au NPs are encapsulated into the pores of the UiO-66 film prepared in situ on a conductive substrate, aggregation of Au nanoparticles could be largely avoided, which promotes the catalytic activity and electron transfer of electrode materials. Therefore, the optimized Au nanoparticles/UiO-66 film sample presented a remarkable electrochemical response toward detection of H2O2 with an extended linear range (0.2–23 mM), a low detection limit (0.045 μM, S/N = 3), high sensitivity (329 μA mM–1 cm–2), and good stability. Furthermore, the as-prepared H2O2 sensor also displayed the advantages of excellent anti-interference performance owing to the size selectivity of the regular triangular opening channel of the UiO-66 film. Combining these advantages, the proposed sensor may open a pathway for high-performance electrochemical sensors and bioelectronics.

{P4Mo6}-Based Complex Modified by Graphite Applied in Electrochemical Ultra-trace Detection of Nitro-antibiotics under Strongly Acidic Conditions

“…The decrease in sensitivity of 1 /GP-GCE may be due to the excessive concentration of interferents. Therefore, the 1 /GP-2.6 composite still exhibited a remarkable anti-interference capability in the complicated system. − …”

Electrochemical immunosensor for rapid and highly sensitive detection of SARS-CoV-2 antigen in the nasal sample

“…UiO-66 (Universitetet i Oslo-66) is a Zirconium (IV) carboxylate MOF made up of inorganic Zr6-octahedra bounded to twelve terephthalates ligands, which offers a high surface area and porosity, excellent thermal conductivity, enrichment capability, and chemical stability [ 7 ]. Due to their affordable costs and superior electrocatalytic activity, transition metals-UiO-based nanostructure have recently been extensively studied for modifying electrochemical sensors [ [8] , [9] , [10] , [11] , [12] ]. However, the issue of UiO-66's low electrical conductivity should be addressed to expand the detection concentration range for the analyte and boost the sensor's adsorption capacity.…”

Selectively Confined Poly(3,4-Ethylenedioxythiophene) in the Nanopores of a Metal–Organic Framework for Electrochemical Nitrite Detection with Reduced Limit of Detection

“…As a unique category of nanoporous materials with fascinating characteristics such as ultrahigh specific surface area and tunable intraframework functionality, metal–organic frameworks (MOFs) have been intensively explored over the past two decades for a variety of applications. − Though the practical use of most MOFs is restricted by their relatively poor chemical stability, , the development of water-stable group 4 metal-based MOFs, e.g. , zirconium-based MOFs (Zr-MOFs), has allowed the use of MOFs in aqueous environments while preserving their structural integrity. ,, Such features further facilitated the application of these MOFs in various chemical sensors for aqueous samples since the spatially dispersed active sites for sensing immobilized within the highly porous framework should result in a high sensitivity and a short response time. − Following this thought, thin films of highly porous group 4 metal-based MOFs incorporated with electroactive sites were thus considered as attractive candidates for electrochemical sensors. For example, the Zr-MOF constructed from porphyrinic linkers could be utilized in the electrochemical detection of nitrite, a common food additive and pollutant, owing to the electrocatalytic activity of the porphyrinic moieties for nitrite oxidation .…”