Long-term stable pH sensor array with synergistic bilayer structure for 2D real-time mapping in cell culture monitoring

Abstract

Pursuing accurate, swift, and durable pH sensors is important across numerous fields, encompassing healthcare, environmental surveillance, and agriculture. In particular, the emphasis on real-time pH monitoring during cell cultivation has become increasingly pronounced in the current scientific environment—a crucial element being diligently researched to ensure optimal cell production. Both polyaniline (PANi) and iridium oxide (IrOx) show their worth in pH sensing, yet they come with challenges. Single-PANi-layered pH sensors often grapple with diminished sensitivity and lagging responses, while electrodeposited IrOx structures exhibit poor adhesion, leading to their separation from metallic substrates—a trait undesirable for a consistently stable, long-term pH sensor. This paper introduces a bi-layered PANi-IrOx pH sensor, strategically leveraging the advantages of both materials. The results presented here underscore the sensitivity enhancement of binary-phased framework, faster response time, and more robust structure than prior work. Through this synergistic strategy, we demonstrate the potential of integrating different phases to overcome the inherent constraints of individual materials, setting the stage for advanced pH-sensing solutions.