A high sensitivity and flexibility detection sensor for oxygen concentration based on polyanionic cellulose/locust bean gum/polyacrylamide hydrogel combination

Abstract

Recent developments in new materials for healthcare and wearable electronics highlight the potential of hydrogels, renowned flexibility, biocompatibility, and adaptability. Composite hydrogels have significant capability for applications requiring multifunctional performance. However, the gas-sensitive components used in traditional gas sensors lack properties such as self-adhere, self-heal, or stretch. This paper introduces a novel composite flexible oxygen-sensitive material composed of polyanionic cellulose (PAC), which is rich in carboxyl groups, locust bean gum (LBG) enhances hydrogel adhesion, and polyacrylamide (PAM) forming a network with diverse interaction sites. The integration of the hydrogel composite with Potassium persulfate (KPS) and N, N¹ methylene bis (acrylamide) AR (MBA) led to improved performance outcomes. Using the hydrogel's distinctive characteristics, the oxygen sensor demonstrates exceptional stretchability of up to 1533 %, gas selectivity, and stable performance under varying humidity conditions, the sensor performs optimally at 40 % relative humidity (RH). Resistance measurements show a sharp increase from tens of ohms to 4.8–5.3 kΩ when exposed to O₂ at the 8-s mark, maintaining this level during exposure. Notably, the sensor demonstrates no significant resistance change in response to N₂ over time. The proposed PAC/LBG/PAM (PLP) hydrogel offers advantages such as excellent stretchability, self-healing ability, electrical conductivity, strong adhesion to organic and inorganic materials, operation at low temperatures, adsorption of nanoparticles, operation under various humidity levels, shortening wound healing period, and selectivity and detection of oxygen gas. The novel hydrogel holds the potential for application in various fields, including flexible sensor production, water management, and wearables.