Sustainable electrochemical sensor from CO2 laser pyrolyzed green leaves for carbendazim detection

The use of green leaves as a substrate for electrochemical sensor production is a sustainable and innovative alternative to conventional materials. Also, CO₂ laser pyrolysis facilitates electrode fabrication on various substrates, promoting high-performance, eco-friendly, and cost-effective sensors. In this work, we used the green leaf as a substrate for sensors from S. macrophylla, a tree species that is abundant and easily accessible in Brazil. For this purpose, we adjusted the laser cutting parameters such as distance, power, and speed to improve the analytical signal. For the electrochemical measurements, the leaves were treated with 0.3 mol L⁻¹ sodium citrate to improve performance and stability. This electrochemical sensor was characterized through electrochemical and morphological analysis. The proposed sensor was applied for Carbendazim (CBZ), a fungicide that protects plants from fungal diseases and poses health risks, including carcinoma, in humans. For this analyte, the sensor presented a linear range of 0.5 to 10 μmol L⁻¹, with a detection limit of 0.1 μmol L⁻¹. CBZ was detected by using addition and recovery tests in tap water, orange juice, and honey, and the values varied from 90.6 % to 101.1 %. This study demonstrates that electrochemical sensors made from dehydrated green leaves exhibit effective analytical performance, high repeatability, and reproducibility, highlighting their potential as sustainable alternatives to traditional sensor substrates.