Glassy Carbon Electrodes Modified with Ordered Mesoporous Silica for the Electrochemical Detection of Cadmium Ions

Abstract

Four different samples of ordered mesoporous silica powders (MCM-41 and SBA-15) and amino-functionalized mesoporous silica (MCM-41-NH 2 and SBA-15-NH 2 ) were used to prepare modified glassy carbon electrodes coated with ion-exchange polymer Nafion to be used for the electrochemical detection of Cd(II). The mesoporous silica samples were characterized through transmission electron microscopy, small-angle X-ray scattering, and N 2 -adsorption/desorption isotherms. The electrodes were characterized by using square wave anodic stripping voltammetry. The effect of pH and of the silica type on the electrodes’ response was investigated. The influence of amino functional groups grafted on the silica surface toward Cd(II) ion detection was also examined. The detection limits determined with the new silica-modified electrodes [between 0.36 and 1.68 μM Cd(II)] are slightly higher than those reported in the literature, but they are lower than those stipulated in the European legislation [45 μM Cd(II)] and, consequently, the electrodes could be successfully used to detect Cd(II) in aqueous solutions.

Tripeptide Derivative-Modified Glassy Carbon Electrode: A Novel Electrochemical Sensor for Sensitive and Selective Detection of Cd2+ Ions

“…Furthermore, a comparison of various literature reported sensors performance for detection of cadmium ions with our novel designed electroanalytical sensor Cbz-APL/GCE is presented in Table . ,,,,− ,− As summarized in comparative Table , limit of detection (LODs) of graphene, carbon nanotubes, nanoparticles, nanocomposites, simple amino acids, surfactants, and polymer-fabricated sensors are considerably inferior to our developed tripeptide-based sensor. These results infer superior properties of our tripeptide-based sensor and excellent stability because of its insolubility in aqueous solutions.…”

“…The electrochemical sensors used to fabricate working electrodes are generally conductive polymers, biomaterials, surfactants, nanomaterials, graphene, and CNTs. − The chemical structure of bio-ligands alike enzymes and proteins possesses electron-rich species like N, O, and S that provide strong and selective binding toward various metal ions for their structural, regulatory, and catalysis functions . These special binding abilities and highly accessible adsorption sites of peptides make them superior candidates as molecular receptors and to exhibit better detection ability and sensitivity when employed for fabrication of heavy metal sensors.…”

Rationally engineered nanosensors: A novel strategy for the detection of heavy metal ions in the environment

“…Their sensitivity to target metals can be improved by adding appropriate functional groups onto the surface [116]. Sacara et al [117] used four types of ordered mesoporous silica powders (MCM-41 and SBA-15) and amino-functional mesoporous silica (MCM-41-NH 2 and SBA-15-NH 2 ) to detect Cd(II). They modified GCE coated with ion-exchange polymer Nafion®.…”

Development of Cd (II) Ion Probe Based on Novel Polyaniline-Multiwalled Carbon Nanotube-3-aminopropyltriethoxylsilane Composite

“…Therefore, to address this problem, a fast, reliable, and sensitive method is required. An electrochemical method fits this, as it is speedy, reliable, suitable for in situ analysis, and cheap [15,16]. Therefore, the current study employs the electrochemical method for Cd 2+ detection in water.…”