Simultaneous Determination of Iron and Copper in Ethanol Fuel Using Nafion/Carbon Nanotubes Electrode

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Glucose biosensor based on multisegment nanowires exhibiting reversible magnetic control

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization and Quantification of the Compounds of the Ethanolic Extract from Caesalpinia ferrea Stem Bark and Evaluation of Their Mutagenic Activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

On-line monitoring of electrochemical degradation of paracetamol through a biomimetic sensor

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of biomimetic sensor for fast and sensitive detection of Norfloxacin

A biomimetic sensor is proposed as a promising new analytical method for determination of norfloxacin (NF) in pharmaceuticals. The sensor was prepared by modifying a glassy carbon electrode surface with a Nafion® membrane doped with poly(copper phthalocyanine) complex [poly-CuPc]. Amperometric measurements carried out with the sensor under an applied potential of -0.05 V vs Ag|AgCl in 0.1 mol L-1 acetic acid containing 1.5 × 10-3 mol L-1 hydrogen peroxide showed a linear response range from 2.0 × 10-4 to 1.2 × 10-3 mol L-1. Selectivity and interference studies were also performed. A sensor response mechanism is proposed, based on the experimental evidence. Recovery studies were carried out using environmental samples, in order to evaluate the sensor’s potential for use with these sample classes. Finally, sensor performance was evaluated using analyses of commercial formulations.

Voltammetric behaviour of a modified electrode with azide copper octa(3-aminopropyl)octasilsesquioxane composite in the oxidation of ascorbic acid

A novel nanostructured composite, azide copper octa (3-aminopropyl)octasilsesquioxane (ASCA) was incorporated into a graphite paste electrode and the electrochemical studies were conducted with cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode with ASCA (GPE-ASCA), showed one redox couple with formal potential (E  ) = 0.30 V and an irreversible process at 1.1 V (vs Ag/AgCl; NaCl 1.0 mol L-1 ; v = 20 mV s-1 ). The redox couple with (E  ) = 0.30V presents an electrocatalytic response for determination of ascorbic acid. The modified electrode gives a linear range from 1.010-4 – 1.010-3 mol L-1 (r = 0.998) for the determination of ascorbic acid with detection limit of 6.910-5 mol L-1 and standard deviation of 2.3% for n = 3 . The amperometric sensitivity was 122.1 mA/mol L-1 for ascorbic acid. The application this electrode was tested and ascorbic acid in three commercial pharmaceutical product (Cebion, Cewin and Redoxon) have been determined.

Desenvolvimento de sensores eletroquímicos e métodos de extração em fase sólida baseados em sistemas biomiméticos para análise de poluentes ambientais

Pós-graduação em Química - IQ

Preparação e Modificação Química de Nanoestruturas de Octa(aminopropil) silsesquioxano para Aplicações Analíticas

Pós-graduação em Ciência dos Materiais - FEIS

Estudo fitoquímico de extratos polares e infusão das folhas de Terminalia catappa L. (Combretaceae) e avaliação de suas atividades antiulcerogênica e mutagênica

Pós-graduação em Química - IQ

Estudo das propriedades estímulo responsivas dos polímeros escovas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Terminalia catappa L.: A medicinal plant from the Caribbean pharmacopeia with anti-Helicobacter pylori and antiulcer action in experimental rodent models

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of uronic acids in sugarcane bagasse by anion-exchange chromatography using an electrode modified with copper nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemical composition and antiproliferative activity of Acalypha californica

Acalypha californica Benth., is a plant in the northwestern region from Mexico, commonly known as "cancer herb" and used in traditional medicine for treating cancer. In the present study we have investigated the antiproliferative activity of methanolic extract of A. californica and its fractions in cancer cell lines and phytochemical analysis and mechanism of apoptosis of the fractions with antiproliferative activity. The antiproliferative activity of methanol extract and its fractions of solvents were evaluated by MTT assay against the M12.A(k).C3.F6, RAW 264.7, HeLa and L929 cell lines. Active fractions were fractionated by molecular exclusion chromatography, HPLC and MPLC. The identification of compounds was performed by NMR and FIA-ESI-IT-MS/MS analysis. Apoptotic mechanism was analyzed by flow cytometry, determining the reduction in the mitochondrial membrane potential (JC-1) and the activity of caspases 3,8 and 9. Cell viability assays showed that the hexane fraction of the methanol extract of the plant has significant effects against cancer lines RAW 264.7 (IC50 = 52.08 +/- 1.06 mu g/mL) and HeLa (IC50 = 46.77 +/- 1.09 mu g/mL), the residual fraction showed a selective effect on cell lines M12.A(k).C3.F6 (IC50 = 59.90 +/- 1.05 mu g/mL), RAW 264.7 (IC50 = 58.93 +/- 1.26 mu g/mL) and HeLa (IC50 = 50.11 +/- 1.135 mu g/mL) compared to the control cell line L929 (IC50 = 100.00 +/- 1.09 mu g/mL). The chemical characterization of the active fractions allowed the identification of p-sitosterol and stigmasterol in hexane fraction and some phenolic acids, proanthocyanidins and flavonoids in the residual fraction. The methanol extract and hexane fraction reduces mitochondrial membrane potential significantly and activates caspases 3, 8 and 9. Because of the antiproliferative activity observed, our results provide a rational basis for the use of extracts of A. californica in treating various types of cancer in traditional medicine from Mexico. The extracts induce apoptosis via activation of caspases. (C) 2015 Elsevier B.V. All rights reserved.

beta-Lactamase-based biosensor for the electrochemical determination of benzylpenicillin in milk

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biochemical capacitance of geobacter sulfurreducens biofilms

An electrical model able to decouple the electron pathway from microbial cell machinery impedance terms is introduced. In this context, capacitance characteristics of the biofilm are clearly resolved. In other words, the model allows separating, according to the advantage of frequency and spectroscopic response approach, the different terms controlling the performance of the microbial biofilm respiratory process and thus the directly related electricity production process. The model can be accurately fitted to voltammetry measurements obtained under steady-state conditions and also to biofilm discharge amperometric measurements. The implications of biological aspects of the electrochemical or redox capacitance are discussed theoretically in the context of current knowledge with regard to structure and physiological activity of microbial Geobacter biofilms.