The Elaboration of Effective Coatings for Photonic Crystal Chips in Optical Biosensors.

Svetlana Sizova,Tatiana Mitko,Fedor Shirshikov,Dmitry Basmanov,Elena Alieva,Julia Bespyatykh,Valery Konopsky,Dmitry Klinov,Ruslan Shakurov,Daria Solovyeva

doi:10.3390/polym14010152

Abstract

Here, we propose and study several types of quartz surface coatings designed for the high-performance sorption of biomolecules and their subsequent detection by a photonic crystal surface mode (PC SM) biosensor. The deposition and sorption of biomolecules are revealed by analyzing changes in the propagation parameters of optical modes on the surface of a photonic crystal (PC). The method makes it possible to measure molecular and cellular affinity interactions in real time by independently recording the values of the angle of total internal reflection and the angle of excitation of the surface wave on the surface of the PC. A series of dextrans with various anchor groups (aldehyde, carboxy, epoxy) suitable for binding with bioligands have been studied. We have carried out comparative experiments with dextrans with other molecular weights. The results confirmed that dextran with a Mw of 500 kDa and anchor epoxy groups have a promising potential as a matrix for the detection of proteins in optical biosensors. The proposed approach would make it possible to enhance the sensitivity of the PC SM biosensor and also permit studying the binding process of low molecular weight molecules in real time.

Highlights

Strategies for attaching biomolecules on a sensitive surface of biosensor substrate while maintaining its identity, structural conformation, and functionality are an evolving field of research
We propose an approach to increase the sensitivity of the photonic crystal surface mode (PC SM) biosensor based on preliminary treating the photonic crystal (PC) chip sensitive surface with organosilanes followed by the formation of a 3D-branched coating from functionalized dextran
We suppose that the proposed approach would make it possible to enhance the sensitivity of the PC SM biosensor and permit studying the low molecular weight molecules’ binding process in real time

Summary

Introduction

Strategies for attaching biomolecules on a sensitive surface of biosensor substrate while maintaining its identity, structural conformation, and functionality are an evolving field of research. The most common methods to carry out such functionalization are electro- and photopolymerization [1,2], self-assembled monolayer [3,4], plasma polymerization [5,6], layer-by-layer deposition [7] and liquid phase deposition [8] Such modifications allow the control of surface properties and the addition of new functionalities such as biocompatibility, chemical stability, antimicrobial activity, new electrical and optical properties, etc. These methods may be complex, limited to certain surfaces, laborious, time consuming, and sometimes poorly reproducible

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