Rapid CO₂-laser scribing fabrication of an electrochemical sensor for the direct detection of Pb²⁺ and Cd²⁺

Laser-induced graphene (LIG) is a highly promising preparation material for electrochemical sensors; however, its preparation speed and nanomaterial modification steps significantly limit its mass production. Herein, this study proposed a new laser printing strategy that considerably improved the preparation speed of LIG with excellent electrochemical performance. Using the optimal parameters (laser power of 1%, scribing spacing of 0.12 mm, and scribing speed of 100 mm·s⁻¹), it took only 14.2 s to complete the preparation of the detection electrode. Thus, we successfully detected Cd²⁺ and Pb²⁺ without any toxic reagents or electrode modification steps. The limits of detection of the sensor were 0.914 and 0.916 μg·L⁻¹ for Cd²⁺ and Pb²⁺, respectively, which are significantly lower than the required values for drinking-water quality, according to the World Health Organization guidelines. This study provides a novel approach for the rapid detection of heavy-metal ions.