Fig. 3.

The effect of the graphene-modified silver electrode design on the sensitivity of the paper chip. (A, B) Impedance spectroscopy and magnitude at 10 kHz of diluted PBS samples on Maze 2 (A, B), Maze 3 (C, D), and Maze 4 (E, F) chips. The least diluted PBS samples that showed significantly different impedance magnitudes compared to DI on Maze 2, Maze 3, and Maze 4 chips were 10% PBS, 0.01% PBS, and 0.0001% PBS, respectively. All error bars are SEM based on repeating the experiments three times (n = 3).