Study of the affinity of Rotavirus with probiotic PEGylated proteins: Development of adapters for the characterization of liquid samples in the spectroscopic ellipsometer of the Universidad Distrital

Abstract

The characterization of liquid samples by means of the spectroscopic ellipsometry (SE) technique requires, for its optimization, the use of sample holders that prevent measurement errors caused by the surface tension of the liquids, optimization of the signal-to-noise ratio, as well as the lack of control of a fixed thickness, among others. This work is part of a project that aims to study the affinity of Rotavirus with PEGylated probiotic proteins through different characterization techniques, including SE. Since the samples considered are liquids (saline solution (SS) and polyethylene glycol (PEG) suspended in SS), we developed different sample holders adaptable to the spectroscopic ellipsometer of the Universidad Distrital, for the indicated purposes. The calibration of these adapters and the measurement technique is achieved, in the first instance, with trial-and-error tests guided by reliability criteria derived from the contrast of our results against those reported in the literature for the case of well-known substances (water, alcohol and oil). The calibration is complemented with the measurement of the optical pseudo-constants of PEG suspended in SS at different concentrations. For this, use is made of empirical (Sellmeier and Cauchy) and physical (Lorentz) dispersion models as well as effective medium approximation theories. As a result, we have configured a device capable of maintaining liquid samples in conditions suitable for characterization by SE.