Modulating the Electrochemical Response of Eco‐Friendly Laser‐Pyrolyzed Paper Sensors Applied to Nitrite Determination

Abstract Miniaturized paper‐based electrochemical sensors were fabricated using kraft paper and CO2 laser, dispensing the need for chemical reagents and controlled atmospheric conditions. This study initially evaluated the paper type and laser processing parameters, enhancing the electrodes′ robustness, electrochemical response, and electrical resistance. The sensors were also treated by applying −1 V for 60 s in 1.0 mol L−1 KCl, which is a simple and rapid procedure. The electrochemical treatment increased the electroactive area and roughness, confirmed by scanning electron microscopy. These aspects helped modulate the sensors′ electrochemical response for nitrite determination, improving selectivity and sensitivity for this compound. The sensors also showed repeatability and batch‐to‐batch reproducibility, with 2.2 and 10 % RSD, respectively. Therefore, this work brings a protocol to fabricating competitive electrochemical sensors through a sustainable strategy, opening possibilities for designing new analytical systems.