Real-Time, in Situ Monitoring of Nitric Oxide and Hydrogen Peroxide Generated By Non-Thermal Plasma Irradiation: Use of an Amperometric Microsensor Array

Abstract

Plasma is high energy electromagnetic radiation. Recently a non-thermal plasma treatment has been employed in emerging new biomedical applications, including bacterial decontamination and chronic wound treatment. Such antimicrobial and healing efficacies may be related to the formation of reactive oxygen and nitrogen species (ROS and RNS; e.g., OH·–, O2·–, NO, ONOO·–, and H2O2) by plasma treatment. Among several reactive species, nitric oxide (NO) has been extensively studied due to its phagocytic and antithrombotic activities, and angiogenic property. In addition, hydrogen peroxide (H2O2), another major species produced by plasma treatment is implicated as the main transmitter of a redox signal in several biological processes. To elucidate bioplasma science, it is essential to real-time, in-situ determine NO and H2O2 produced during plasma treatment and their generation kinetics. Herein we report on a microsensor array to selectively detect NO and H2O2 generated by non-thermal plasma irradiation, respectively. Two working electrodes (Pt for NO sensing and Pt/aniline derivative for H2O2 sensing, respectively) are modified with a perfluorinated xerogel as a permselective membrane to improve sensor’s selectivities over readily oxidizable interfering species and other ROS and RNS. In addition, the effect of the plasma gas composition (O2/N2 ratio) on NO/H2O2 production ratio will be studied. Finally the microarray sensor will be employed to determine NO and H2O2 generation during plasma irradiation in biological milieu in vivo or ex vivo.