Interactions of a biological macromolecule with thermotropic liquid crystals: Applications of liquid crystals in biosensing platform

[Display omitted] •Detection of bovine serum albumin (BSA) by 4′-octyl-4-biphenylcarbonitrile (8CB) liquid crystals (LCs)•Temperature and concentration behaviour of the mixture detected by POM.•The director configuration of 8CB on addition of BSA showed transition under a POM.•Detection of BSA by 8CB LC was confirmed at a concentration of 100 µM of BSA.•Molecular docking and Raman spectroscopy were the novel techniques employed.•The distribution of binding energy −8.80 Kcal/mol; most favourable docking position is subdomain IB. Liquid crystal biosensor was developed based on a 4′-octyl-4-biphenylcarbonitrile (8CB) by adsorption of biological macromolecule bovine serum albumin (BSA) at the 8CB interface. BSA was detected by examining the changes in the director configurations of 8CB molecules under a polarizing optical microscope. The transitions in the director configuration were due to the non-covalent bonds. This technique demonstrated high sensitivity at a concentration of 100 µM of BSA. The binding events between the 8CB and BSA were investigated through molecular docking studies that confirmed the protein-ligand interaction. The most probable binding location of 8CB to dock with BSA were determined at a subdomain IB of Sudlow’s site I. The active residues on analyzing were found to stabilize the 8CB molecules through different interactions. These active residues that were involved in the protein-ligand interaction were further confirmed with Raman spectroscopy. This study provided the vibrational properties and structural changes that occurred due to the various interactions between the 8CB and BSA. The results presented in this work lead to a potential biosensing tool for detecting and sensing proteins using LCs.