Electronic Supplementary Material
A highly sensitive nonenzymatic glucose sensor based on NiO-modified multi-walled carbon nanotubes
Wei-De Zhanga, ,Jin Chena, Liao-Chuan Jianga, Yu-XiangYua, Jia-Qi Zhangb
aNano Science Research Center, School of Chemistry and Chemical Engineering, South China University of Technology, 381 Wushan Road, Guangzhou 510640, P. R. China; bCollege of Environmental Science and Safety Engineering, Tianjin University of Technology, Tianjin 300071, P. R. China
The influence of scan rate on the current response for the anodic current (Ipa) of glucose oxidation was studied and the result is indicated in Fig. S1.
Fig. S1(A) Representative CVs of the NiO/MWCNTs electrode at different scan rates, 10, 20, 30, 40, 50, 60, 70, 80, 90, 130, 150 mV·s-1 (a-l) in 0.10 M NaOH solutioncontaining 6.0 mM glucose. (B) The plot of oxidative peak current with scan rate.
Optimization conditions for the NiO/MWCNTs electrode
To improve the performance of the sensor, the effect of the applied potential on the response current of the sensor is demonstratedby amperometric method in Fig. S2. When the applied potential was increased from +0.40 to +0.60 V, the maximum response current was observed at +0.50 V, that is,the optimal applied potential was obtained at +0.50 V in 0.10 M NaOH solution. Therefore, +0.50 V was used for the subsequent experiments. In addition, the influence of the NaOH concentration on the response current of the sensor was also investigated by CVs, as shown in Fig. S3A.When the concentration of NaOH solution was changed from 0.05 M to 0.20 M, the peak potential of oxidation of glucose was gradually decreased and the peak current of 3.0 mM glucose was gradually increased until it reached 0.20 M and then decreased with further increase the concentration of NaOH (Fig. S3B). Thus, the concentration of NaOH solution of 0.20 M was selected as the supporting electrolyte.
Fig. S2Effect of applied potential on the response current in 0.10 M NaOH solution containing 1.0 mM glucose.
Fig. S3 (A) CVs of different concentration of NaOH solution at the NiO/MWCNTs electrode. (B) The relationship of the peak current and peak potential with concentration of NaOH solution. Scan rate:100 mV·s-1; Concentration of glucose: 3.0 mM.
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