properties. Figure (c) shows VDP against nH with a correlation coefficient of r = 0.61. This finding is reasonable because VDP is sensitive to charge doping. Nonetheless, the nH values were measured in air and before the electrical measurement in the aqueous solution. Thus, the spatial variations in VDP predominantly stemmed from nH fluctuations, with minimal influence from factors such as ions in the solution on the VDP variations across the array. Unlike VDP, IDS,min, gmh, and gme did not correlate with nH (Figure ). These values are largely influenced by contact resistance, rendering estimating them via the current Raman analysis challenging, as the imaging area was positioned in the middle of the channels and did not include the contact regions between the electrodes and graphene.