Argon Cold Atmospheric Pressure Plasma-Induced Effects on Glucose

The aim of this study was to evaluate the effects of CAP plasma on glucose. Plasma treatments were performed using an argon-driven atmospheric pressure plasma device whose discharge environment was initially characterized by optical emission spectroscopy. Each sample was subjected to plasma treatments of increasing duration, up to 16 min. X-ray photoelectron spectroscopy analysis was performed to determine the atomic concentrations of carbon, nitrogen, and oxygen of the outermost surface and to identify the chemical bonding states, revealing significant oxidation of the surface and minor incorporation of nitrogen. Attenuated total reflectance Fourier-transform infrared spectra of each sample were recorded, from which the intensity evolution of the relevant bands over time was derived. The IR spectra indicate an opening of the glucopyranose ring in glucose, suggesting its enveloping degradation due to plasma treatment at different exposition durations with CAP plasma. In addition, reactive oxygen and nitrogen species in the plasma discharge caused the formation of C=O as part of carboxylic groups and small amounts of carbon-nitrogen moieties or carbon-carbon double bonds in the plasma-treated samples.