Functionalized Graphene Nanocomposite Research Articles

Facile coordinating decoration of salophen Al on graphene nanosheet: Salophen Al complex functionalized graphene nanocomposite with electrochemical properties

Salophen Al complex functionalized graphene (SCFG) nanocomposite was synthesized by simple coordination of phenol functionalized graphene (PFG) and as-prepared salophen Al complex. This process is facile, convenient and high efficient. We also investigated the structure, optical properties and electrochemical properties of the obtained SCFG composites. The results showed that salophen Al conjugated and incorporated onto the graphene sheet surface and the composites maintained the micro-structure of graphene sheets without agglomeration. The photoluminescence of salophen Al was completely quenched by graphene, due to the charge transfer between the salophen Al and the graphene nanosheets. Moreover, a significant electrochemical signal emerged on the SCFG modified electrodes compared with those of the graphene sheets or salophen Al complex. Owing to preliminary results of the excellent electrochemical property, SCFG nanocomposite is a promising electrochemical redox probe material.

Synthesis of neutral red covalently functionalized graphene nanocomposite and the electrocatalytic properties toward uric acid

The preparation of neutral red covalently-functionalized graphene nanosheets (NR-FGN) is presented via replacement of the carboxyl acid groups at the edges of graphene nanosheets using NR. The obtained NR-FGN was characterized by UV-vis, Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). It was found that the introduction of NR at the edges of graphene nanosheets (GN) improved the solubility and stability of the graphene. The electrochemical impedance result further confirmed that NR-FGN could effectively accelerate the electron transfer. Due to the synergic effect between GN and NR, the nanocomposite exhibited excellent electrocatalytic activity toward the oxidation of uric acid.

Sensitive detection of acetaminophen based on Fe3O4 nanoparticles-coated poly(diallyldimethylammonium chloride)-functionalized graphene nanocomposite film

An electrochemical sensor based on Fe3O4 nanoparticles (NPs)-coated poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene (Fe3O4-PDDA-G) nanocomposite was fabricated for sensitive detection of acetaminophen. The nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The electrochemical behaviors of acetaminophen on Fe3O4-PDDA-G composite film modified glassy carbon electrode (GCE) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The experimental results indicated that the incorporation of Fe3O4 NPs with PDDA-G greatly enhanced the electrochemical response of acetaminophen. This fabricated sensor displayed excellent analytical performance for acetaminophen detection over a range from 0.1 to 100μmolL−1 with a detection limit of 3.7×10−8molL−1 (S/N=3). The redox peaks of acetaminophen, dopamine (DA) and ascorbic acid (AA) can be well separated on the Fe3O4-PDDA-G/GCE. Moreover, the proposed electrochemical sensor also exhibited good reproducibility and stability, and has been used to detect acetaminophen in tablets with satisfactory results.

Sensitive detection of esculetin based on a CdSe nanoparticles-decorated poly(diallyldimethylammonium chloride)-functionalized graphene nanocomposite film

An electrochemical sensor based on a CdSe nanoparticles (NPs)-decorated poly(diallyldimethylammonium chloride) (PDDA)-functionalized graphene (CdSe-PDDA-G) nanocomposite was fabricated for the sensitive detection of esculetin. The nanocomposite was characterized by X-ray diffraction (XRD), ultraviolet/visible spectra (UV-vis) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behaviors of esculetin on the CdSe-PDDA-G composite film-modified glassy carbon electrode (GCE). The experimental results indicated that the incorporation of CdSe NPs with PDDA-G greatly enhanced the electrochemical response of esculetin. This electrochemical sensor displayed satisfactory analytical performance for esculetin detection over a range from 1.0 × 10(-8) to 5.0 × 10(-5) mol L(-1) with a detection limit of 4.0 × 10(-9) mol L(-1) (S/N = 3). Moreover, the sensor also exhibited good reproducibility and stability, and could be used for the detection of esculetin in real samples with satisfactory results.