Interaction of the Fluorescent Cell-Labeling Dye Rhodamine 6G with Low-Molecular-Weight Compounds: A Comparative QCM Study of Adsorption Capacity of Rh6G for Gaseous Analytes

Abstract

Rhodamine 6G is widely used in biochemistry and cell imaging as a sensitive layer of chemical sensors. At the same time, the features of the interaction of Rh6G with low-molecular-weight analytes present in most biochemical preparations have not been studied. In this study, the interaction of Rh6G thin films with water vapor, acetic acid, ethyl alcohol, ammonia, benzene, pyridine, nitrobenzene, acetone, and acetonitrile in the gas phase was studied. The kinetic features and adsorption capacity of the sensitive layer were compared with those of other sensitive layer materials (macrocyclic dibenzotetraazaanulenes, phthalocyanines, and their metal complexes). The response values of the Rh6G-based sensor significantly exceed the responses of other sensors, regardless of the type of analyte. This means that this material is promising for multivariate sensor arrays, where the issue of cross-selectivity is a prerequisite. However, when developing selective sensors or when using Rhodamine 6G for analytical analysis in biochemistry, the ability of Rh6G to interact with a wide range of low-molecular-weight analytes must be taken into account.

Keywords

• QCM sensor
• Rhodamine 6G
• adsorption
• absorbance
• low-molecular-weight analytes