A correlation analysis between the G and 2D peak frequencies revealed a threshold dose above (below) which ID/IG was dominated by doping (strain). By comparing CVD-grown graphene with mechanically exfoliated graphene, we showed that this trend is universal, but the threshold values may vary due to differences in their initial defect densities. Future work will involve improving the pattern resolution down to the few-nm level, as well as studies on gases other than water vapor. Through our systematic studies, we uncovered the effects of the various ESEM parameters and show how defects can be engineered with great precision in graphene, thereby expanding the range of next-generation applications with respect to sensing and optoelectronics.