(660c) Binding and Dissociation Kinetics of Different Analytes On Novel Biosensing Surfaces: A Fractal Analysis

A fractal analysis is presented for the binding and dissociation (if applicable) of different analytes in solution to different biosensing surfaces. The analysis includes: (a) the binding of different IgG species to a porous SiO2 interferometric biosensor coated with protein A (Schwartz et al., 2007), (b) binding (hybridization) using a differential surface plasmon resonance biosensor(Boecker et al., 2007), (c) binding indicating the time course of glucose measurement by One Touch II blood glucose meter, and by a SERS sensor (Stuart et al., 2006), (d) binding of different concentrations (in nM) of con A to a colloidal gold coated with a glycolipid/dodecanethiol bilayer biosensor (Guo et al., 2007), and (e) the binding of H9 avian influenza virus to calcium quantum dots (Yun et al., 2007). The fractal analysis provides a quantitative measure of the degree of heterogeneity on the sensing surface, and links this degree of heterogenety on the sensing surface to the binding and dissociation (if applicable) coefficients.

In some cases, a single-fractal analysis is adequate to describe the binding and the dissociation (if appliable) kinetics (Corel Quattro Pro 8.0). If the regression analysis indicates that the fit is not adequate (regression coefficient less than 0.97), only then does one resort to a dual-fractal analysis.

The versatility of the fractal analysis is demonstrated by its successful application to the kinetics of different analyte/receptor systems occurring on the different biosensing systems. The analysis provides fresh physical insights into the reactions occurring on these sensing surfaces. Predictive relations that are developed are particularly useful since they provide a means by which the different parameters such as the binding and the dissociation rate coefficients, and thereby the corresponding affinities may be manipulated in desired directions.