Figures & data
Figure 1. (A) Cyclic voltammograms of (a) UCPE, (b) Fe3O4-CPE, (c) BQ-CPE and (d) BQ-Fe3O4-CPE at 10 mVs‐1, (B) curve of the anodic peak current versus the square root of the scan rate for Fe3O4-CPE (inset: cyclic voltammograms at scan rates of 10, 25, 50, 75, 100 and 150 mVs−1) in 0.1 M KCl solution containing 1 mM Fe(CN)63−/4−.
![Figure 1. (A) Cyclic voltammograms of (a) UCPE, (b) Fe3O4-CPE, (c) BQ-CPE and (d) BQ-Fe3O4-CPE at 10 mVs‐1, (B) curve of the anodic peak current versus the square root of the scan rate for Fe3O4-CPE (inset: cyclic voltammograms at scan rates of 10, 25, 50, 75, 100 and 150 mVs−1) in 0.1 M KCl solution containing 1 mM Fe(CN)63−/4−.](/cms/asset/86f09e14-b627-4ec3-a563-39925ef121c4/ianb_a_712045_f0001_b.gif)
Figure 2. The Nyquist curves of (a) UCPE and (b) Fe3O4-CPE (c) BQ-CPE and (d) BQ-Fe3O4 CPE in 0.1 M KCl solution containing 1 mM Fe(CN)63−/4−.
![Figure 2. The Nyquist curves of (a) UCPE and (b) Fe3O4-CPE (c) BQ-CPE and (d) BQ-Fe3O4 CPE in 0.1 M KCl solution containing 1 mM Fe(CN)63−/4−.](/cms/asset/8cf71ad1-115f-4a21-bcbf-52f603f4f109/ianb_a_712045_f0002_b.gif)
Figure 3. (A) Calibration curves for H2O2: (a) BQ‐Fe3O4‐CPE, (b) Fe3O4‐CPE (c) BQ‐CPE and (d)UCPE (0.05 M pH 7.5 phosphate buffer, + 0.30 V, nitrogen-saturated solution). (B) Calibration curves for glucose: (a) BQ‐Fe3O4‐CPEE, (b) Fe3O4‐CPEE (c) BQ‐CPEE and (d) UCPEE (0.05 M pH 7.5 phosphate buffer, + 0.30 V, oxygen-saturated solution).
![Figure 3. (A) Calibration curves for H2O2: (a) BQ‐Fe3O4‐CPE, (b) Fe3O4‐CPE (c) BQ‐CPE and (d)UCPE (0.05 M pH 7.5 phosphate buffer, + 0.30 V, nitrogen-saturated solution). (B) Calibration curves for glucose: (a) BQ‐Fe3O4‐CPEE, (b) Fe3O4‐CPEE (c) BQ‐CPEE and (d) UCPEE (0.05 M pH 7.5 phosphate buffer, + 0.30 V, oxygen-saturated solution).](/cms/asset/963d00b3-d2d5-412a-93da-5415aff3981f/ianb_a_712045_f0003_b.gif)
Figure 4. The effect of buffer pH on the response of Fe3O4‐CPEE (0.05 M phosphate buffer, + 0.30 V).
![Figure 4. The effect of buffer pH on the response of Fe3O4‐CPEE (0.05 M phosphate buffer, + 0.30 V).](/cms/asset/af6863f8-f95e-4869-ac06-91c925e5baf0/ianb_a_712045_f0004_b.gif)
Figure 5. (A) Effect of glucose concentration on the response of Fe3O4‐CPEE (B) Effect of glucose concentration on the response of BQ‐Fe3O4‐CPEE (inset: glucose response of the BQ‐Fe3O4‐CPEE at low concentrations) (0.05 M, pH 7.5 phosphate buffer, + 0.30 V, oxygen-saturated solution).
![Figure 5. (A) Effect of glucose concentration on the response of Fe3O4‐CPEE (B) Effect of glucose concentration on the response of BQ‐Fe3O4‐CPEE (inset: glucose response of the BQ‐Fe3O4‐CPEE at low concentrations) (0.05 M, pH 7.5 phosphate buffer, + 0.30 V, oxygen-saturated solution).](/cms/asset/0414e523-a6ab-490c-9dee-f3b47deeef7d/ianb_a_712045_f0005_b.gif)
Table 1. Comparison of glucose concentration in serum samples using the modified enzyme electrode and the spectrophotometric method.