We presented a rapid, extensive, and high-resolution inspection technique for GFET arrays using slit-scanning Raman microscopy. Raman imaging of entire arrays within 30 min per chip was achieved. Our findings revealed a correlation between nH, determined through vectordecomposition of (ωG, ω2D) and VDP across a range of graphene qualities, followed by solutiongated electrical measurements. Notably, nH values were measured in ambient conditions before electrical testing in an aqueous solution, suggesting that VDP variations predominantly stemmed from nH fluctuations rather than solution-induced effects. For applications such as biosensors, precharacterization in ambient conditions is crucial, as measurements in solution may cause irreversible changes due to ion adsorption and intercalation. The analysis of (ωG, ω2D) across fabrication stages revealed that spatial variations in Raman peaks and thus VDP fluctuations were established during the wet-transfer process. This finding can help refine the fabrication process. Although this study focused on nH and VDP relationships within a solution-gated configuration, these insights apply broadly to top-and back-gated GFETs, as VDP depends on nH and gate capacitance regardless of gate configuration.