Investigation of DNA–cationic bolaform surfactants interaction with different spacer length

In this paper interaction of DNA with cationic bolaform surfactants is investigated. The structural formula for synthesized bolaforms is as follows: bolaform B1 with structural formula Br−(CH3)3N+(CH2)3N+(CH3)Br− and bolaform B2 with structural formula of Br−(CH3)3N+(CH2)12N+(CH3)Br−. There are stronger electrostatic interactions in bolaform B1 due to shorter spacer length, while there are stronger hydrophobic interactions in bolaform B2 compared to bolaform B1 due to existence of 12 carbons in hydrocarbonic chain. The structure of bolaforms consists of two polar head groups which play important role in DNA compaction. Surface tension change in aqueous solution of bolaform surfactants is measured using tensiometer. Electrical conductivity of surfactants aqueous solution is examined with and without DNA. DNA compaction is tracked in the presence of bolaforms by dynamic light scattering (DLS) technique. Results of DLS indicate bolaforms with shorter spacer length (dominant electrostatic interactions) are more influential in compressing DNA compared to bolaforms with longer spacer length (stronger hydrophobic interactions). UV–vis and fluorescence spectroscopies specify the binding mechanism of bolaform surfactants to DNA.