Plasma-assisted dyeing of polyester-cotton blend fabrics with ninhydrin-based azo disperse dyes: surface modification, coloration behavior, and antimicrobial functionality.

Plasma-assisted surface modification is an environmentally friendly strategy for improving textile dyeability; however, previous studies have primarily focused on conventional disperse dyes or single-component polyester fabrics, with limited understanding of multifunctional dyeing systems for polyester-cotton blends. In this work, a series of novel ninhydrin-based azo disperse dyes were synthesized and applied to polyester-cotton (70/30) blend fabrics pretreated using atmospheric-pressure dielectric barrier discharge plasma jet (DBD-JET) and low-pressure capacitively coupled plasma (CCP). Plasma-induced surface modifications were investigated by XRD, SEM, FT-IR, Raman spectroscopy, and contact-angle measurements, while dyeing performance, antimicrobial activity, molecular docking, ADMET, and cytotoxicity were evaluated. Plasma treatment increased the crystallinity of the fabric from 59% to 67% after short exposure and significantly enhanced surface roughness, oxygen-containing functional groups, and wettability, while XRD indicated no major alteration of the polyester-cotton phase composition. These modifications resulted in improved color strength and excellent fastness properties. Among the synthesized dyes, compounds 4a and 4b exhibited the highest antimicrobial activity and the strongest binding affinities toward DNA gyrase, with docking scores of -9.8099 and -8.9698 kcal mol-1, respectively, together with favorable ADMET and cytotoxicity profiles. The combined use of complementary plasma treatments and newly synthesized ninhydrin-based azo disperse dyes provides an effective strategy for producing multifunctional polyester-cotton textiles with enhanced dyeing performance and antimicrobial functionality.