Reduced graphene oxide functionalized zinc octaethyl porphyrin (rGO/Zn OEP) for selective detection of carbon monoxide in chemiresistive modality

An innovative chemiresistive sensor design capitalizes on the unique properties of reduced graphene oxide (rGO) functionalized with zinc octaethyl porphyrin (Zn OEP), establishing an exceptionally discriminative and sensitive platform for detecting carbon monoxide (CO). Employing a meticulously synthesized graphene oxide (GO) via a modified Hummers method, followed by a judicious thermal reduction process to yield rGO. The resultant rGO suspension was intricately deposited onto accurately fabricated gold-coated microelectrodes on a glass substrate using the precise shadow mask technique. The sensor’s efficacy was significantly enhanced through the discerning functionalization of the rGO surface with Zn OEP porphyrin. Comprehensive characterization encompasses structural, spectroscopic, electrical, and morphological analyses of the synthesized materials. The rGO/Zn OEP sensor exhibits remarkable selectivity and sensitivity in response to CO. Notably, the developed sensor achieves a striking limit of detection (LOD) of 1 ppm for CO, demonstrating rapid response/recovery time (25 s/33 s) along with an outstanding linear response (R² = 0.98) at room temperature. This pioneering sensing platform showcases precision CO detection capabilities, underscoring its potential for advanced environmental monitoring and safety applications.