23^rd European Biotechnology Congress

Biography

Biography: Carolina Paz Quezada

Abstract

The sun is the most clean, abundant and available source of renewable energy. First generation solar cells allow the conversion of solar radiation into electricity with an effi ciency of ~25%. Nevertheless, photovoltaic market is evolving to improve production costs, effi ciency and sustainability. New generation of solar cells are sensitized with diff erent molecules like dyes, nanoparticles and more recently proteins have been tested as photosensitizers. In this study, a redox protein (azurin) coupled to CuInS2 quantum dots (QDs) are used as photosensitizers in a Grätzel solar cell. Th e azurin gene was identifi ed within the genome of a strain from our collection of Antarctic bacteria (Pseudomonas fl uorescens 198). Th is gene was cloned and overexpressed in E. coli, and the His-tag purifi ed azurin + CuInS2 QDs were incorporated in a sensitized solar cell, using TiO2 as anode and Pt as counter electrode. In our laboratory, biomimetic and biosynthesized nanoparticles of CdS and CuInS2, among others, have been successfully used as photosensitizers. Preliminary studies have indicated an increase in 56% of the effi ciency when the azurin is incorporated to the cell, compared to the cell sensitized only with CuInS2 QDs. Th e effi ciency is also improved when CdS QDs are coupled to the azurin (42%). Th e most stable orientation of the His-tag azurin in the TiO2 layer is being studied by hybrid quantum mechanics/molecular mechanics (QM/MM) calculations, in order to determine if any particular position favors the electron transference to the anode.