Not yet reviewed by Pith; the record is open.

The goal of the present study is to explore how the size and functionalization of graphene quantum dots (GQDs) affect their sensing capabilities. Specifically, we investigated the adsorption of SO$_2$, SOF$_2$, SO$_2$F$_2$, and SF$_6$ on GQDs that were functionalized with -CH$_3$, - COCH$_3$, and -NH$_2$. We used density functional theory to analyze the electronic properties of these functionalized GQDs and found that the functionalization significantly altered their electronic properties. For example, the B3LYP H-L gap of pristine triangulene was 3.9eV, while the H-L gap of functionalized triangulene ranged from 2.8 eV-3.6 eV (using the B3LYP functional). Our results indicate that -NH2 functionalized phenalenyl and triangulene provide strong interaction with SO$_2$, with adsorption energies of -0.429 eV and -0.427 eV, respectively. These adsorption properties exhibit physisorption, leading to high gas sensitivity and superior recovery time. The findings of this study provide new insights into the potential use of GQDs for detecting the decomposed constituents of sulfur hexafluoride, which can be beneficial for assessing the operation status of SF$_6$ insulated devices. Overall, our calculations suggest that functionalized GQDs can be employed in gas insulated systems for partial discharge detection.