Novel electrochemical sensor based on functionalized graphene for simultaneous determination of adenine and guanine in DNA.

A nano-material carboxylic acid functionalized graphene (graphene-COOH) was prepared and used to construct a novel biosensor for the simultaneous detection of adenine and guanine. The direct electrooxidation behaviors of adenine and guanine on the graphene-COOH modified glassy carbon electrode (graphene-COOH/GCE) were carefully investigated by cyclic voltammetry and differential pulse voltammetry. The results indicated that both adenine and guanine showed the increase of the oxidation peak currents with the negative shift of the oxidation peak potentials in contrast to that on the bare glassy carbon electrode.

Label-free amperometric immunobiosensor based on a gold colloid and Prussian blue nanocomposite film modified carbon ionic liquid electrode.

A novel experimental methodology based on a Prussian blue (PB) and gold nanoparticles (AuNPs) modified carbon ionic liquid electrode (CILE) was developed for use in a label-free amperometric immunosensor for the sensitive detection of human immunoglobulin G (HIgG) as a model protein. The CILE was fabricated by using the ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate as binder. Controllable electrodeposition of PB on the surface of the CILE and coating with 3-aminopropyl triethylene silane (APS) formed a film with high electronic catalytic activity and large surface area for the assembly of AuNPs and further immobilization of HIgG antibody.

Direct electrochemistry and electrocatalysis of hemoglobin on carbon ionic liquid electrode.

Hemoglobin in agarose was successfully immobilized on a carbon ionic liquid electrode and the direct electrochemical behavior of hemoglobin was investigated. Room temperature ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate was used as the modifier. Ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy and cyclic voltammetry were used to characterize the hemoglobin on the modified electrode.

A disposable electrochemical immunosensor for carcinoembryonic antigen based on nano-Au/multi-walled carbon nanotubes-chitosans nanocomposite film modified glassy carbon electrode.

In this paper, a disposable electrochemical immunosensor for the detection of carcinoembryonic antigen (CEA) based on Au nanoparticles (AuNPs)/multi-walled carbon nanotubes (MWCNTs)-chitosans (Chits) composite film was developed. MWCNTs-Chits homogeneous composite was first dispersed in acetic acid solution and then the AuNPs was in situ synthesized at the composite. The mixture was dripped on the glassy carbon electrode (GCE) and then CEA antibody (anti-CEA) was immobilized on the resulted modified electrode to construct the immunosensor.