Quantitative analysis of molecular interactions between erythrosine B and cationic surfactants: liquid crystal-based sensor design for the efficient determination of erythrosine B

Erythrosine B (EB) is a xanthene dye widely used in many fields such as food, cosmetics and medicine. The interaction between EB and cetyltrimethylammonium bromide (CTAB) was investigated using spectrophotometry. The quantities of the quenching constant of Stern-Volmer, the number of binding sites and the binding constant were calculated for the EB-CTAB system. Liquid crystal-based sensing platform (LC) developed for ultrasensitive and unlabelled EB determination using an LC interface decorated with cationic surfactants. Nematic liquid crystals exposed to CTAB exhibited homeotropic binding, when EB was inserted into LC cells, and the inward arrangement was thus changed to a coplanar shape by electrostatic interaction between CTAB and EB. The sensor was developed based on LC which recognised EB at tracking level too low, up to 2.0 pM. The proposed LC-based sensing system is a quick, comfortable and easy approach for the determination of EB in unlabelled biological samples.

Automated summary

The interaction between Erythrosine B (EB) and cetyltrimethylammonium bromide (CTAB) was investigated, and the quenching constant, binding sites, and binding constant were calculated for the EB-CTAB system using spectrophotometry. A liquid crystal-based sensing platform (LC) was developed, which utilized an LC interface decorated with cationic surfactants to achieve ultrasensitive and unlabelled EB determination. The LC-based sensing system recognized EB at a remarkably low level, down to 2.0 pM, making it a fast, convenient, and effective method for the determination of EB in unlabeled biological samples.