Extended Gate Transistor‐based Multi‐biomarker Sensing Platform for Real‐time Urine Analysis

Abstract Urine analysis stands as a critical diagnostic tool, offering insights into health and disease. However, current techniques demand sophisticated equipment or significant sample processing for urine examination, reducing their suitability for regular point‐of‐care assessments. This study introduces a novel multi‐component sensing platform to address these constraints. The proposed sensor array can detect sodium (Na⁺), potassium (K⁺), ammonium (NH₄⁺), calcium (Ca⁺⁺), chloride (Cl⁻), and pH levels, thus, enabling real‐time urine analysis. This sensing platform utilizes an extended gate (EG)‐field effect transistor (FET) design employing EG electrodes made of LASER engraved graphene on flexible Kapton substrates. These experimental findings from individual sensors demonstrate consistent linear responses to ion levels, discrimination of specific ions among interferences, and operational stability over time. Additionally, the six‐channel sensor array exhibits notable sensitivity and selectivity in a urine environment, effectively discerning various ions and pH, illustrating its efficacy for urine analysis and validating its potential for reliable point‐of‐care diagnostics.