Fig.3
The optimization of electroplating time to fabricate GNE for nucleic acid sensing. The SEM images of the top views (a) and side views (b) of GNEs with deposition time of 100 s, 200 s and 300 s (left to right). The comparison of diameter (c) and height (d) of GNEs with different deposition time based on the SEM images of a and b, respectively. e The changes of the “petals” to “bud” ratio of GNEs with the deposition time characterized by SEM imaging. f The CV scans of GNEs with different deposition time in 10 mM H2SO4 with a scan rate of 0.05 V/s. g The ECSAs calculated from CVs obtained in f. h The comparison of the detection performance of 1 pM DNA-21 among the three different sizes of GNEs. The control group was the hybridization buffer without DNA-21. (i) The S/N ratio calculated from h. N ≥ 3 per group, ns: not significant, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001