Influence of NaCl concentration on reactive species formation in plasma-activated saline solutions using coaxial DBD

Autor(es)

Miranda, Felipe de Souza ; Azevedo Neto, Nilton Francelosi ; Koga-Ito, Cristiane Yumi ; Pessoa, Rodrigo Savio

• Tipo de documento: Artigo Científico
• Fonte: PHYSICA SCRIPTA; v. 100, n. 7, p. 13-pg., 2025-07-01.

Resumo

Plasma-Activated Saline Solutions (PAS), derived from Plasma-Activated Water (PAW), are increasingly recognized for their versatile applications in infection control, wound healing, and sterilization. These solutions are produced by exposing liquids to cold plasma, generating a rich mixture of reactive oxygen and nitrogen species (RONS) and reactive chlorine species (RCS). This study investigates the production of PAS using a coaxial dielectric barrier discharge (DBD) operating with compressed air and evaluates the impact of varying sodium chloride (NaCl) concentrations (0.9%, 1.8%, 3.6%, and 7.2%) on the generation of RONS and RCS. Deionized water (DI water) was also activated as a baseline comparison. Physicochemical properties, including pH, oxidation-reduction potential (ORP), conductivity, and total dissolved solids (TDS), were measured before and after plasma activation. Real-time UV-Vis and Raman spectroscopy were employed to monitor the formation and stability of reactive species. To complement the UV-Vis data, additional analytical methods, such as colorimetric test strips and estimations based on pH and equilibrium constants, were employed. The analyses revealed that NaCl concentration significantly influences the composition and behavior of PAS, with lower concentrations favoring the generation of RONS such as nitrites ( NO2- ) and nitrates ( NO3- ), while higher concentrations modulate the production of RCS like hypochlorous acid (HClO). The results demonstrated a pronounced decrease in pH and an increase in ORP, indicating enhanced oxidative and antimicrobial potential. Spectroscopic analyses revealed distinct patterns of RONS formation, including NO3- , NO2- , H2O2, and HClO, with notable interactions between RCS and RONS at higher NaCl concentrations. These findings underscore the dynamic interplay between ionic strength, reactive species production, and solution stability, providing critical insights into optimizing PAS for biomedical applications. The study highlights PAS's potential as eco-friendly, residue-free alternatives for disinfection and wound care, offering tailored properties based on NaCl concentration to meet specific therapeutic needs. (AU)

• Processo FAPESP: 21/14181-3 - Desenvolvimento e estudo de um sistema de plasma gerado por descarga de barreira dielétrica (DBD) para ativação contínua de líquidos aplicados em tratamentos odontológicos.
• Beneficiário: Felipe de Souza Miranda
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 22/11544-0 - EMU tecnológico: aquisição de um sistema de microscopia óptica de varredura de campo próximo acoplado com microscopia de força atômica e espectroscopia Raman aprimorada por ponta para imageamento químico e físico em micro e nanoescala
• Beneficiário: Rodrigo Savio Pessoa
• Modalidade de apoio: Auxílio à Pesquisa - Programa Infraestrutura - Tecnologia e Inovação
• Processo FAPESP: 19/05856-7 - Aplicações de plasmas atmosféricos não-térmicos na odontologia: da bancada para a clínica
• Beneficiário: Cristiane Yumi Koga Ito
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 23/02268-2 - Geração e caracterização de diferentes líquidos ativados com plasma para aplicação no tratamento endodôntico
• Beneficiário: Nilton Francelosi Azevedo Neto
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado