Usando una escala de 1-5 indique el progreso que ha logrado con relación a las metas que estableció en su blog del 27 de enero.
· 1 – ningún progreso, no he logrado ningún de los objetivos propuestos.
· 2 – algo de progreso, he logrado al menos 10% de los objetivos propuestos.
· 3 – progreso intermedio, he logrado al menos 50% de los objetivos propuestos.
· 4 – mucho progreso, he logrado al menos 80% de los objetivos.
· 5 – excelente progreso, he logrado todos los objetivos para esta fecha.
Este mes ha sido uno fuerte, y con relación a mis metas no he podido lograr mucho.
¿Qué dificultades ha afrontado en relación a sus metas? ¿Qué ha hecho para atenderlas?
Ha sido la misma este semestre el sol-gel no ha querido pegarse al electrodo bien. He repetido ya el experimento más de cuatro veces. Para atender este problema hice una búsqueda en la literatura y voy a leer para ver si logro encontrar algún tip para poder facilitar la interacción solgel/HbI/electrodo. A pesar de este mal tiempo, este mes estaré presentando la investigación en el PRISM (este año en la Universidad de Rio Piedras), el sábado 14, de marzo de 2009. También, el sábado 21, de marzo de 2009 presentaré el Poster de la investigación en la Planta Piloto en Mayagüez. La primera auspiciada por PRLSAMP y la segunda por Bio MINDS.
Development of a Biosensor using HbI of Lucina Pectinata with
Purification Methods and Characterization by Electroanalytical Technique
Abstract
The hemoglobin HbI is produced by Lucina pectinata, a clam that uses it to transport H2S. This protein is intended to be use as a biosensor to detect the presence of H2S and, in order to do it, is important to study its electrochemical properties. The Cyclic Voltammetry technique is an electrochemical method used in analytical chemistry and various industrial processes, which was used to study the electrochemical properties in several biomaterials. Cyclic Voltammetry measures the faradic current while the potential is varied when oxidation and reduction processes occurred. This method was used to analyze the electron transfer kinetics of four different proteins: Cytochrome-c, Hemoglobin, Myoglobin and HbI using Glassy Carbon (GC) electrode as working electrode. Multi-Walled Carbon Nanotubes (MWCNT) were used to improve the signal obtained from the proteins in the cyclic voltammograms. The carbon nanotubes absorb the protein into their surface producing an interaction, which facilitates the electron transfer, giving better signals. Also, this work reports the purification methods for recombinated HbI and HbI/Sol-gel (TMOS) electrode, arranged by intermolecular interactions of the recombinant hemoglobin I from Lucina pectinata and TMOS (tetramethyl orthosilicate) in a carbon paste electrode. The spectra UV-Vis revealed that the protein is highly purified, showing recognized bands for two hemoglobin species. On the other hand, a pair of well-defined redox peaks for HbI[Fe(III)–Fe(II)] was obtained at the prepared electrode by direct electron transfer between the protein and sol-gel. Electrochemical parameters of immobilized hemoglobin such as formal potential (E°’), charge transfer coefficient (α) and apparent heterogeneous electron transfer rate constant (ks) were estimated by cyclic voltammetry and nonlinear regression analysis. The results suggested that the redox process was an adsorption-controlled and the immobilized hemoglobin was stable. Biocatalytic activity will be exemplified at the prepared electrode for redox process of hydrogen sulfide in future works and electron-transfer process in sol-gel still under investigation.
