Neste trabalho de revisão são analisados os avanços mais recentes em eletrodos enzimáticos amperométricos dando ênfase particular aos biosensores baseados na Glucose Oxidase e na Horseradish Peroxidase. A intermediação redox através de mediadores artificiais solúveis ou ligados a polímeros é discutida em termos dos desenvolvimentos teóricos recentes e verificações experimentais. É analisada a d...

A disposable amperometric immunosensor was developed for the detection of Plasmodium falciparum histidine-rich protein 2 (PfHRP-2) in the sera of humans with P. falciparum malaria. For this purpose, disposable screen-printed electrodes (SPEs) were modified with multiwall carbon nanotubes (MWCNTs) and Au nanoparticles. The electrodes were characterized by cyclic voltammetry, scanning electron mi...

Carbon fiber electrodes are crucial for the detection of catecholamine release from vesicles in single cells for amperometry measurements. Here, we describe the techniques needed to generate low noise (<0.5 pA) electrodes. The techniques have been modified from published descriptions by previous researchers (1,2). Electrodes are made by preparing carbon fibers and threading them individually in...

We describe the in vivo characterization of microamperometric sensors for the real-time monitoring of nitric oxide (NO) and oxygen (O₂) in the striatum of immunocompromised NOD SCID mice. The latter strain has been utilized routinely in the establishment of humanized models of disease e.g., Parkinson's disease. NOD SCID mice were implanted with highly sensitive and selective NO and O₂ sensors t...

A high sensitive and stable amperometric biosensor was developed using cholesterol oxidase, chitosan and multiwall carbon nano tubes (MWCNT’s) in order to determine total cholesterol in serum samples. Cholesterol oxidase was covalently immobilized on MWCNT’s; this enzyme was coated over glassy carbon electrode (GCE) and then a layer of chitosan deposited to prevent enzyme leaching. The ChOx/MWC...

Although synaptophysin is one of the most abundant integral proteins of synaptic vesicle membranes, its contribution to neurotransmitter release remains unclear. One possibility is that through its association with dynamin it controls the fine tuning of transmitter release. To test this hypothesis, we took advantage of amperometric measurements of quantal catecholamine release from chromaffin c...

Poly(3,4-ethylenedioxythiophene)-Pt nanoparticle composite was synthesized in one-pot fashion using a photo-assisted chemical method, and its electrocatalytic properties toward hydrogen peroxide (H2O2) was investigated. Under UV irradiation, the rates of the oxidative polymerization of EDOT monomer along with the reduction of Pt4+ ions were accelerated. In addition, the morphology of PtNPs was ...