Interfacial Modeling of Fibrinogen Adsorption onto LiNbO3 Single Crystal-Single Domain Surfaces.

Jeffrey S Cross,Abhijit Chatterjee,Motohiro Tagaya,Yasuhiro Kubota,Toshiyuki Ikoma,Samir Unni

doi:10.3390/ijms22115946

Abstract

For the development of next-generation protein-based biosensor surfaces, it is important to understand how functional proteins, such as fibrinogen (FBG), interact with polar substrate surfaces in order to prepare highly sensitive points of medical care diagnostics. FBG, which is a fibrous protein with an extracellular matrix, has both positively and negatively charged regions on its 3-dimensional surface, which makes interpreting how it effectively binds to polarized surfaces challenging. In this study, single-crystal LiNbO3 (LNO) substrates that have surface charges were used to investigate the adsorption of FBG protruding polar fragments on the positively and negatively charged LNO surfaces. We performed a combination of experiments and multi-scale molecular modeling to understand the binding of FBG in vacuum and water-solvated surfaces of LNO. XPS measurements showed that the FBG adsorption on LNO increased with increment in solution concentration on surfaces independent of charges. Multi-scale molecular modeling employing Quantum Mechanics, Monte Carlo, and Molecular Mechanics addressed the phenomenon of FBG fragment bonding on LNO surfaces. The binding simulation validated the experimental observation using zeta potential measurements which showed presence of solvated medium influenced the adsorption phenomenon due to the negative surface potential.

Highlights

LiNbO3 (LNO) is a widely used material for high-frequency surface acoustic wave (SAW) devices used in smartphones, etc., for bandpass filtering due to its piezoelectric characteristic
−10,651.34 (MD) calculations were performed with the LNO surface constrained; the water molecules
We compared experimental observations of preferential binding of FBG over LNO both in the gas phase and solvent phase to examine the dependency of surface polishing

Summary

Introduction

LiNbO3 (LNO) is a widely used material for high-frequency surface acoustic wave (SAW) devices used in smartphones, etc., for bandpass filtering due to its piezoelectric characteristic. Since LNO is a piezoelectric material, it has ferroelectric bipolar domains, which exhibit an internal electric field, which extends outside of its surfaces [3]. This electric field is known to influence the freezing point of liquids and other physical properties of materials in which they are in direct physical contact [4]. Because of these interesting combinations of properties, LNO has much potential for use as a biosensor either in optical or electronic applications [5,6].

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