Silver Nanoparticles‐Silsesquioxane Nanomaterial Applied to the Determination of 4‐Nitrophenol as a Biomarker

Abstract

A novel silsesquioxane material was synthetized and used as a stabilizing agent for silver nanoparticles. This hybrid material was characterized by FTIR, 29Si CP‐MAS NMR, 13C DEPT 135° NMR and TGA techniques and the silver nanoparticles were characterized from DLS, UV‐Vis spectroscopy, zeta‐potential, TEM and SAXS results. The silver nanoparticles obtained were spherical in shape with a diameter of 3.74 nm. The nanomaterial was successfully applied in the modification of a glassy carbon electrode and a pronounced current response was obtained in the determination of the biomarker 4‐nitrophenol. Quantum chemical calculations, using density functional theory, were also performed in order to evaluate the redox properties of the analyte. Two different linear ranges were obtained applying optimal square wave voltammetry conditions. The reduction peak currents obtained were linear for 4‐NP concentrations in the ranges of 0.29 to 1.50 μmol L−1 (Ed=−0.6 V and td=20 s) and 2.75 to 31.5 μmol L−1, with a theoretical (signal to noise=3) limit of detection of 0.05 μmol L−1 (td=20 s). The proposed method was successfully applied to the determination of 4‐NP in synthetic serum samples at different levels of 4‐NP with a recovery range of 94–101 %. Validation was performed using a comparative method through the capillary electrophoresis (CE) technique.

Core–Shell Chitosan Cobalt Ferrite Nanoparticles for Ultrasensitive Simultaneous Voltammetric Determination of Pb(II) and Cd(II)

“…For instance, bismuth film combined with nanomaterials, such as carbon nanotubes, reduced graphene oxide, and clay materials, has been reported as sensitive modified electrodes for uranium, cadmium, and lead . In general, the numerous available redox sites, coupled with the electrocatalytic effect of nanomaterials, have been explored as a powerful tool for determining organic pollutants. − The high surface-to-volume ratio of nanoparticles can be harnessed in stripping voltammetric analysis, enhancing analyte preconcentration onto the electrode surface . Moreover, the primary challenge in heavy metal determination is to obtain an inert nanomodified electrode in the cathodic potential range.…”

Highly Luminescent and Water-Stable CsPbCl3/Mn2+/PEG Nanocrystals for Ultrasensitive Detection of 4-Nitrophenol

“…To date, many strategies have been designed for the detection of 4-NP, including liquid chromatography-tandem mass spectrometry, 8,9 electrochemistry, 10−12 capillary electrophoresis, 13,14 photoelectrochemistry, 15 and high-performance liquid chromatography. 16,17 However, these methods require expensive equipment, complex sample pretreatment, or electrode modification and have long detection times, limiting their widespread application.…”

“…To date, many strategies have been designed for the detection of 4-NP, including liquid chromatography-tandem mass spectrometry, , electrochemistry, − capillary electrophoresis, , photoelectrochemistry, and high-performance liquid chromatography. , However, these methods require expensive equipment, complex sample pretreatment, or electrode modification and have long detection times, limiting their widespread application. Among these methods, fluorescence spectroscopy has been receiving increasing attention due to its simplicity, rapid response, high sensitivity, and selectivity. , Various fluorescence methods for detecting 4-NP have been developed, including inorganic nanomaterials, organic fluorescent dyes, , semiconductor quantum dots (QDs), , and metal–organic framework materials, which possess excellent physical and chemical properties.…”

Layer-By-Layer Films of Silsesquioxane and Nickel(II) Tetrasulphophthalocyanine as Glucose Oxidase Platform Immobilization: Amperometric Determination of Glucose in Kombucha Beverages

“…There are specific methods to immobilize enzymes on the electrode surface combined with the LbL technique. 3-n-propylpyridinium silsesquioxane chloride (SiPy + Cl − ) and its analogues are hybrid organic-inorganic materials that possess highly advantageous properties in biosensing such as biocompatibility and high chemical stability [24,25]. Nickel(II) phthalocyanine-tetrasulfonic acid tetrasodium salt (Nitsch) is an inorganic complex that possesses valuable characteristics in electrochemical sensors [26,27], such as a good thin film former, a conjugated π system that can add electronic properties to the system, and the anionic nature of the complex that makes it accessible for adsorption in cationic materials.…”