Electrochemical response characteristics of the proposed SPE sensors.
| Parameter | Bare SPE | Functionalized SPE | Au NP SPE |
|---|---|---|---|
| Slope (mV per decade) | −57.5 | −58.3 | −59.05 |
| Intercept (mV) | 229.33 | 235.8 | 249.05 |
| Correlation coefficient | 0.9994 | 0.9998 | 0.9996 |
| LOD (M) | 7.9 × 10−6 | 7.6 × 10−6 | 6.8 × 10−6 |
| Response time (sec) | 15 | 15 | 10 |
| Isothermal coefficient (V °C−1) | 0.00189 | 0.00187 | 0.00184 |
| Working pH range | 4–8 | 4–8 | 4–8 |
| Concentration range (mol L−1) | 10−5–10−2 | 10−5–10−2 | 10−5–10−2 |
| Stability (months) | 5 | 6 | 7 |
| Accuracy (% R) | 100.78 | 101.12 | 99.62 |
| Precision (% RSD) | |||
| Repeatabilitya | 1.345 | 0.987 | 0.659 |
| Intermediate precisionb | 1.453 | 0.876 | 0.531 |
| Robustnessc (mean ± % RSD) | 99.02 ± 1.026 | 98.45 ± 1.106 | 99.32 ± 0.872 |
a
Average of three different concentrations (1 × 10−4, 1 × 10−3 and 1 × 10−2 mol L−1) repeated three times within a day.
b
Average of three different concentrations (1 × 10−4, 1 × 10−3 and 1 × 10−2 mol L−1) repeated three times in three days.
c
Variation in method parameters such as the pH of the sample.