Non-thermal plasma efficiently decontaminates sensitive materials from respiratory viruses.

INTRODUCTION

Heat- and moisture-sensitive porous materials such as plush toys, paper products, and foam are widely used in pediatric and healthcare environments but cannot be decontaminated by conventional liquid disinfectants, heat, or UV-based methods. This creates a need for alternative dry, non-thermal technologies. Non-thermal plasma (NTP) offers a promising approach for disinfecting such materials without compromising their integrity.

METHODS

In this study, we assessed the virucidal efficacy of a prototyped NTP device on four clinically relevant respiratory viruses-Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), Influenza A virus (IAV), human Adenovirus (HAdV), and human Rhinovirus (HRV)-applied to paper, plush fabric, and foam rubber.

RESULTS

Material characterization by SEM and XPS demonstrated only mild surface oxidation and no structural damage following NTP exposure. Across all substrates, NTP treatment produced time-dependent reductions in viral infectivity. Maximum reductions ranged from 5.5-6.3 log10 for SARS-CoV-2, 6.3-7.1 log10 for IAV, 4.0-5.9 log10 for HAdV, and 2.7-5.0 log10 for HRV, depending on the virus-material combination. Enveloped viruses (SARS-CoV-2 and IAV) were inactivated more rapidly than the non-enveloped viruses HAdV and HRV, although all viruses were reduced to nearly or completely undetectable levels after 30-60 min of treatment. Several virus-material combinations exhibited biphasic inactivation kinetics characterized by an initial rapid decline followed by a slower phase of inactivation.

DISCUSSION: These findings support that NTP could be an effective, residue-free, and material-preserving method for inactivating a broad spectrum of respiratory viruses on porous substrates incompatible with conventional disinfection. NTP thus might represent a valuable tool for safely reusing sensitive items in pediatric and clinical settings and reducing contamination risks where existing methods are impractical.