Development and characterization of nanostructured films for conductimetric hydrog...
| Grant number: | 10/07478-5 |
| Support type: | Research Grants - Young Investigators Grants |
| Duration: | July 01, 2011 - June 30, 2014 |
| Field of knowledge: | Physical Sciences and Mathematics - Chemistry |
| Principal Investigator: | Valber de Albuquerque Pedrosa |
| Grantee: | Valber de Albuquerque Pedrosa |
| Home Institution: | Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil |
| Associated scholarship(s): | 13/12623-2 - Study of stimulus-responsive properties of polymer brush modified with gold nanoparticle, BP.MS |
Abstract
There is a need for the development of new robust miniaturized biosensors that combine high selectivity of biological systems with enhanced sensitivity of physical devices to monitor complex biomedical analytes, air, food, and water quality. Sensor technology will benefit from a further improvement in the specificity and sensitivity of direct and discriminative detection of various chemical and biological substances, including environmental components, food toxins, and health-related compounds.We propose to develop a new robust biosensor platform that can detect and quantitatively measure multiple analytes based on a biocatalytic conversion of the analyte in enzymatic reactions. The proposed system will explore structural changes of stimuli-responsive nanostructured composite thin films caused by the products of the enzymatic reaction. The changes will result in the generation of analyte-specific optical output signals that will be measured by an efficient and highly sensitive technique: gold nanoparticle-enhanced transmission surface plasmon resonance (T-SPR) spectroscopy.The nanostructured thin film will be composed of a monolayer of gold nanoislands coated by the tethered polymer. The film will be loaded with enzymes and gold nanoparticles. Biocatalytic processes relevant to analyte conversion will be used to initiate chain reaction - free radical polymerization in the film. The chain reaction will be used to amplify the biocatalytic reaction and dramatically increase the device sensitivity up to the level of 10-10 moles of the analyte. The function of the synthesized and cross-linked polymer in the course of radical polymerization is to cause swelling the thin polymer film loaded with gold nanoparticles. The film swelling will lead to a change in the strength of plasmon coupling between the nanoparticles and the nanoislands. This mechanism will be used to trigger changes in the optical properties of the composite film.The major focus of this proposal is on the development of the biosensor platform capable to explore the biocatalytically initiated polymerization process. Such a platform will enable the combination of the biocatalytic process, the chemical amplification, and the plasmonic effect in one device. This approach can be potentially applied to many different biosensing schemes based on enzymes capable of metabolizing target biological analytes in a complex environment. (AU)