Green Fabrication and Analytical Application of Disposable Carbon Electrodes Made from Fallen Tree Leaves Using a CO₂ Laser

The use of materials from nature to prepare sensors is a challenge, once we can generate great value with respect to the environment. In this regard, the carbonization of several types of substrates through the utilization of a CO2 laser promotes the fabrication of exceptional electrochemical sensors that exhibit different architectures, all while adhering to the principles of eco-friendliness and cost-efficiency. In this context, the pursuit of novel substrates derived from renewable sources, characterized by their accessibility and wide availability, is important in the advancement of cutting-edge electrochemical sensors. In this scenario, the study into the utilization of fallen tree leaves is presented for the first time, capitalizing on the pyrolytic transformation induced by a CO2 laser, to fabricate electrochemical sensors. During the sensor fabrication process, the parameters of the CO2 laser, including laser power, pyrolysis scan rate, and scan gap, are systematically adjusted to attain optimal outcomes. The proposed sensors were characterized through electrochemical, morphological, and physicochemical methodologies, thereby enabling an exhaustive exploration of the novel carbonized surface generated on the leaves. Also, to underscore the applicability of the sensors, they have been employed in the detection of dopamine and paracetamol in biological and pharmaceutical samples. The applications of this system show a linear range of 10-1200 mu mol L-1 for dopamine and 5.0-100.0 mu mol L-1 for paracetamol, with limits of detection of 1.1 and 0.76 mu mol L-1, respectively. In this manner, electrochemical sensors derived from fallen tree leaves exhibit satisfactory analytical performance and remarkable reproducibility, thus highlighting their substantial potential to replace conventional substrates.