ZIF-8 Coupling with Reduced Graphene Oxide to Enhance the Electrochemical Sensing of Dopamine

Abstract

A reduced graphene oxide@zeolitic imidazolate framework-8 (rGO@ZIF-8) based electrochemical sensor was developed and used for dopamine detection. ZIF-8 was rapidly prepared by zinc hydroxide nitrate (Zn-HDS, Zn5(OH)8(NO3)2·2H2O) as precursor. Subsequently, rGO was introduced to enhance the performance of ZIF-8 (e.g., high carrier mobility, favorable stability), and a label-free electrochemical dopamine sensor based on the composite material was obtained with high specific surface area and better conductivity verified by Brunauer–Emmett–Teller surface analysis and electrochemical impedance spectroscopy, respectively. Consequently, rGO@ZIF-8 complex exhibited an admirable electrochemical catalytic performance. For determination of dopamine, the sensor behaves wide linear range from 2.0 × 10−6 to 1.4 × 10−4 mol l−1 and lower detection limit of 2.0 × 10−8 mol l−1 (S/N = 3). It also showed sufficient repeatability and durability due to the coordinated amplification effect of rGO and ZIF-8.

Surfactant-Assisted rGO-PbO2 Electrode to Boost Acrylamide Degradation in Industrial Sewage

“…The absorption peaks located at 1397 and 1640 cm –1 in Figure a represent the C–C bond and the C=C double bond, respectively. This phenomenon confirmed the removal of the oxygen-containing group after GO reduction to form C=C Figure b shows that a weak −OH pulling vibration peak appears at 3400 cm –1 , which was caused by the residual incompletely reacted OH and adsorbed water molecules left after GO reduction.…”

Urea Electrooxidation in Alkaline Environment: Fundamentals and Applications

“…Different urea biosensors operate using various transducer mechanisms relying on optical methods, [32] enzymatic approaches, [33] and electrochemical techniques. [34] Optical methods require the use of additional instruments and trained technicians to conduct urea measurements, making them more applicable in professional institutes. [35] Current smartphones have made visual detection possible, increasing the ease and convenience of measuring urea concentration.…”

Enhanced Electrochemical Sensing of Butylated Hydroxy Anisole through Hollow Metal–Organic Frameworks with Gold Nanoparticles and Enzymes

“…Metal−organic frameworks (MOFs) are comprised of metal nodes and organic ligands, which possess high surface areas, homogeneous cavities, and excellent enzyme encapsulation properties. 16 Therefore, the immobilization of enzyme into MOFs is promising owing to its excellent catalytic activity and minimal enzyme leaching. 17−20 In addition, hollow MOFs exhibit better properties than pristine MOFs (solid), including considerable active sites, easier charge carrier transfer, and faster mass transfer.…”

“…Therefore, the choice of the current collector is of paramount importance. Metal–organic frameworks (MOFs) are comprised of metal nodes and organic ligands, which possess high surface areas, homogeneous cavities, and excellent enzyme encapsulation properties . Therefore, the immobilization of enzyme into MOFs is promising owing to its excellent catalytic activity and minimal enzyme leaching. − In addition, hollow MOFs exhibit better properties than pristine MOFs (solid), including considerable active sites, easier charge carrier transfer, and faster mass transfer. − Moreover, the construction of meso-/macropore inside hollow MOFs might enable the accommodation of large-sized enzymes, or speed up their diffusion. , Notably, the existence of noble metal (e.g., Au) can amplify the electrochemical signal due to the abundance of Au(0) active species, resulting in increased sensitivity and lower detection limits …”