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A potentiometric indirect uric acid sensor based on ZnO nanoflakes and immobilized uricase.

Ali SM, Ibupoto ZH, Kashif M, Hashim U, Willander M - Sensors (Basel) (2012)

Bottom Line: The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM).In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity.The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

View Article: PubMed Central - PubMed

Affiliation: Department of Science and Technology, Linköping University, Campus Norrköping, Norrkoping, Sweden. syeal@itn.liu.se

ABSTRACT
In the present work zinc oxide nanoflakes (ZnO-NF) structures with a wall thickness around 50 to 100 nm were synthesized on a gold coated glass substrate using a low temperature hydrothermal method. The enzyme uricase was electrostatically immobilized in conjunction with Nafion membrane on the surface of well oriented ZnO-NFs, resulting in a sensitive, selective, stable and reproducible uric acid sensor. The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM). In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity. The proposed ZnO-NF array-based sensor exhibited a high sensitivity of ~66 mV/ decade in test electrolyte solutions of uric acid, with fast response time. The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

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The sensor to sensor reproducibility of six (n = 6) ZnO-NFs /uricase/Nafion electrodes in 100 μM uric acid solution.
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f5-sensors-12-02787: The sensor to sensor reproducibility of six (n = 6) ZnO-NFs /uricase/Nafion electrodes in 100 μM uric acid solution.

Mentions: To evaluate the performances of the proposed sensor, we have checked the parameters like reproducibility, measuring range, detection limit, response time and selectivity, etc. The reproducibility is an important characteristic for the performance evaluation of a sensor. To evaluate reproducibility and long term stability of the proposed ZnO-NFs based sensors, we independently fabricated six sensor electrodes under the same conditions; the relative standard deviation of the fabricated sensor electrodes in standard uric acid solutions was less than 5%. The sensor to sensor reproducibility in 100 μM uric acid solution is shown in Figure 5.


A potentiometric indirect uric acid sensor based on ZnO nanoflakes and immobilized uricase.

Ali SM, Ibupoto ZH, Kashif M, Hashim U, Willander M - Sensors (Basel) (2012)

The sensor to sensor reproducibility of six (n = 6) ZnO-NFs /uricase/Nafion electrodes in 100 μM uric acid solution.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376584&req=5

f5-sensors-12-02787: The sensor to sensor reproducibility of six (n = 6) ZnO-NFs /uricase/Nafion electrodes in 100 μM uric acid solution.
Mentions: To evaluate the performances of the proposed sensor, we have checked the parameters like reproducibility, measuring range, detection limit, response time and selectivity, etc. The reproducibility is an important characteristic for the performance evaluation of a sensor. To evaluate reproducibility and long term stability of the proposed ZnO-NFs based sensors, we independently fabricated six sensor electrodes under the same conditions; the relative standard deviation of the fabricated sensor electrodes in standard uric acid solutions was less than 5%. The sensor to sensor reproducibility in 100 μM uric acid solution is shown in Figure 5.

Bottom Line: The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM).In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity.The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

View Article: PubMed Central - PubMed

Affiliation: Department of Science and Technology, Linköping University, Campus Norrköping, Norrkoping, Sweden. syeal@itn.liu.se

ABSTRACT
In the present work zinc oxide nanoflakes (ZnO-NF) structures with a wall thickness around 50 to 100 nm were synthesized on a gold coated glass substrate using a low temperature hydrothermal method. The enzyme uricase was electrostatically immobilized in conjunction with Nafion membrane on the surface of well oriented ZnO-NFs, resulting in a sensitive, selective, stable and reproducible uric acid sensor. The electrochemical response of the ZnO-NF-based sensor vs. a Ag/AgCl reference electrode was found to be linear over a relatively wide logarithmic concentration range (500 nM to 1.5 mM). In addition, the ZnO-NF structures demonstrate vast surface area that allow high enzyme loading which results provided a higher sensitivity. The proposed ZnO-NF array-based sensor exhibited a high sensitivity of ~66 mV/ decade in test electrolyte solutions of uric acid, with fast response time. The sensor response was unaffected by normal concentrations of common interferents such as ascorbic acid, glucose, and urea.

Show MeSH