| AVS 59th Annual International Symposium and Exhibition | |
| Spectroscopic Ellipsometry Focus Topic | Monday Sessions |
| Session EL+TF+BI+AS+EM+SS-MoA |
| Session: | Spectroscopic Ellipsometry: From Organic and Biological Systems to Inorganic Thin Films |
| Presenter: | C.D. Garcia, The University of Texas at San Antonio |
| Authors: | T. Benavidez, The University of Texas at San Antonio K. Chumbuni-Torres, The University of Texas at San Antonio J.L. Felhofer, The University of Texas at San Antonio C.D. Garcia, The University of Texas at San Antonio |
| Correspondent: | Click to Email |
Biosensors are analytical platforms that integrate a biological recognition element with a signal transducer. Because they have the potential to provide rapid, real-time, and accurate results, biosensors have become powerful tools in clinical and biochemical settings. Our group is particularly interested in the development of electrochemical biosensors based on enzymes adsorbed to nanomaterials. When integrated to microfluidic devices, these sensors offer sensitivity, portability, low cost, and the possibility of analyzing turbid samples. Adsorption was selected to immobilize the biorecognition element because it is one of the simplest and most benign methods, avoiding cross-linking reactions or additional components (such as entrapping polymers). Most importantly, as adsorption is a required (and sometimes limiting) step for any immobilization mechanism, the identification of key variables influencing this process can be applied to a variety of strategies. Although several techniques have been used to study the adsorption of proteins to nanomaterials,1 only a few of them provide information about the kinetics of the process in real time. This is a critical aspect, as most of the post-adsorption conformational changes occur within a few minutes after the interaction.2 Among those, reflectometry was used by our group to perform the first kinetic study related to the interaction of proteins with carbon nanotubes.3 These kinetic studies have been recently extended to the interaction of enzymes (D-amino acid oxidase,4 catalase,5 and glucose oxidase6) by variable angle spectroscopic ellipsometry, which enabled a more thorough analysis of the interaction process with a much more versatile experimental design.7,8 The use of VASE demonstrated that a number of variables, (being the amount of enzyme only one of them) can influence the biological activity of proteins adsorbed to the substrate. Furthermore, our results indicate that that the activity of enzymes adsorbed to nanomaterials can be directly related to the kinetics of the adsorption process (dG/dt).5
Please see supplemental document for figures and footnotes.