Fig. 3: Characterization of the sensor.
a FTIR spectra to verify the CuAAC reaction between signal unit BPNS@AgNPs-Alkyne and Azide-Fe3O4. The curves are BPNS@AgNPs-Alkyne (green line), Azide-Fe3O4 (orange line), and complex signal unit-Fe3O4 (blue line). b CV and c EIS to characterize the sensor assembly process, where the curves are bare MGCE (blue line), and MGCE + complex signal unit-Fe3O4 (orange line). Experimental conditions: 0.1 mol L−1 KCl containing 5.0 mmol L−1 [Fe(CN)6]3−/4−; potential scan range: −0.2 to 0.6 V vs. Ag/AgCl (3 mol L−1 KCl); scan rate of CV: 50 mV s−1; frequency range and AC amplitude of EIS: 0.01 to 10 kHz, 5 mV. d Feasibility of electrochemical sensor characterized by FSV. Curves shown here are a subset of FSV voltammograms of bare MGCE (orange line), Azide-Fe3O4 (blue line), BPNS@AgNPs-Alkyne (pink line), Azide-Fe3O4 + BPNS@AgNPs-Alkyne (gray line), Azide-Fe3O4 + BPNS@AgNPs-Alkyne + Cu2+ (brown line), Azide-Fe3O4 + BPNS@AgNPs-Alkyne + SA (green line) and Azide-Fe3O4 + BPNS@AgNPs-Alkyne + Cu2+ + SA (violet line), all of which are background subtracted and baselines are all set to 0 as templated as Supplementary Fig. 11. e Identical FSV voltammograms in continuous-cycle mode. The curves are the 1st cycle at 400 V s−1 (orange line), the 800th cycle at 400 V s−1 (gray line). Curves shown here are FSV voltammograms without background subtraction. Experimental conditions of d and e: 0.5 mol L−1 KNO3 containing 1 amol L−1 Cu2+; potential window: −1.0 −1.5 V vs. Ag/AgCl (3 mol L−1 KCl); scan rate: 400 V s−1. Source data are provided as a Source Data file.
