Biochar-Based Screen-Printed Sensors: A Sustainable Solution for Electrochemical Applications

Biochar, a sustainable and cost-effective material derived from biomass, has emerged as a versatile candidate for constructing advanced electrochemical sensors, particularly screen-printed sensors and biosensors. This review explores the utilization of biochar in the fabrication of screen-printed sensors, emphasizing its properties, such as a high surface area, chemical stability, and tunable functionalities, which are crucial for electroanalytical applications. Key factors influencing biochar properties, including feedstock composition, pyrolysis conditions, and activation methods, are thoroughly analyzed. The study highlights the integration of biochar into various screen-printed sensor platforms, demonstrating its effectiveness in enhancing sensitivity, selectivity, and durability across a range of analytes, from pharmaceuticals to environmental pollutants. Furthermore, the review discusses innovative applications, such as biochar-based flexible and wearable devices, biosensors, immunosensors, and resistive humidity sensors, underscoring their potential in real-world applications. Challenges, including variability in biochar properties and limited electrical conductivity, are also addressed, along with future perspectives for improving standardization and performance. By bridging waste valorization with cutting-edge sensor technologies, biochar-derived screen-printed electrodes represent a promising pathway toward sustainable and efficient electrochemical sensing platforms.