Fig. 3

Enhancing the sensitivity of graphene-based sensors and monitoring different molecular layer thicknesses. a Schematic of the graphene-based sensor. Gate voltage modulation enables GP-enhanced detection of molecular signals. b The scanning electron microscopy (SEM) image of the GP-based sensor showcases its distinctive design, characterized by periodic nanoribbons that enhance its sensing capabilities. The width of the graphene nanoribbon is approximately \(50\; \mathrm{nm}\), and the period is approximately \(100\; \mathrm{nm}\). c Direct experimental response of the GP-based sensor with different thicknesses of silk protein and d the response enhanced by synthesized CFW. The characteristic vibrational peak are marked by the vertical line. e The sensitivity characterized by the dip depths \(\Delta h\) in c, d. The inset illustrates how \(\Delta h\) is extracted, which is defined as the vertical distance between the bottom of the dip and the dashed line connecting between the shoulders of the dip