A Highly Selective Real-Time Electroanalytical Detection of Sulfide Via Laser-Induced Graphene Sensor

Herein, a novel miniaturized sensor for sulfide detection is presented. The sensor was fabricated over a flexible polyimide substrate via CO₂ laser ablation followed by surface modification with methylene blue acting as a redox mediator. The sensor showed an acceptable linear detection range (0.5 μM–1 mM), and excellent limit of detection (0.435 μM) and limit of quantification (2.45 μM). Further, remarkable sensitivity of 0.295 μA/(μM mm²) for 0.5–50 μM and 0.0047 μA/(μM mm²) for 100–1 mM was obtained. The signal-to-noise ratio was found to be 2.76 and the performance was validated by real lake water samples.