Fig. 1
Characterization of e-miRchip and the GNE grown on the microaperture arrays. a Photograph of the microaperture array with 15 detection units (Inset: a zoom-in view of the detection unit in the white box labeled area). Each unit contained 6 apertures divided into 2 groups. b The SEM image of the bare microaperture. c SEM images of the GNE and the zoom-in high-resolution images of the red box labeled regions. d CV curves before and after GNE deposition (200 s) in 10 mM H2SO4 with the scan rate of 0.05 V/s. e CV curves of the e-miRchips with the bare aperture, GNE deposition and SLP immobilization on the GNE in 2 mM K3[Fe(CN)6] and 0.1 M KCl solution with the scan rate of 0.05 V/s. f EIS spectra of the e-miRchips in 2 mM K3[Fe(CN)6]/K4[Fe(CN)6] and 0.1 M KCl solution. Inset: Randle’s equivalent circuit, Rs: solution resistance, CPE: constant phase angle element, RCT: charge-transfer resistance