The quality by design approach for optimization of slayer exciter based low power portable atmospheric plasma jet on bactericidal efficacy of Pseudomonas aeruginosa

Abstract

A simple, portable, economical low-temperature atmospheric plasma (LTAP) for bactericidal efficacy of Gram-negative bacteria (Pseudomonas aeruginosa) with different carrier gases (argon, helium, and nitrogen) using the quality by design (QbD) approach, design of experiments (DoE), and response surface graphs (RSG) is presented. Box-Behnken design was used as the DoE to narrow down and further optimize the experimental factors of LTAP. Plasma exposure time, input DC voltage, and carrier gas flow rate were varied to examine the bactericidal efficacy using the zone of inhibition (ZOI). A higher bactericidal efficacy was achieved under the optimal bactericidal factors having ZOI of 50.837 ± 2.418 mm² with the plasma power density of 132 mW/cm³ for LTAP-Ar at 61.19 s, 14.8747 V, and 219.379 sccm than LTAP-He and LTAP-N₂ . The LTAP-Ar was further evaluated at different frequencies and probe lengths to achieve a ZOI of 58.237 ± 4.01 mm² .

Keywords: Box-Behnken design; Pseudomonas aeruginosa; bactericidal efficacy; low temperature atmospheric plasma; zone of inhibition.