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Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite.

Das G, Yoon HH - Int J Nanomedicine (2015)

Bottom Line: The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds.Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C.The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea.

ABSTRACT
An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm(-2)·mM(-1). The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

No MeSH data available.


Cyclic voltammogram of indium tin oxide/sulfonated graphene/polyaniline/urease at different cycles, obtained at 20 mV·s−1. The arrow in the figure indicates increasing cycle from 1st to the 10th.Abbreviation: vs, versus.
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f9-ijn-10-055: Cyclic voltammogram of indium tin oxide/sulfonated graphene/polyaniline/urease at different cycles, obtained at 20 mV·s−1. The arrow in the figure indicates increasing cycle from 1st to the 10th.Abbreviation: vs, versus.

Mentions: In most previous instances of urea biosensors, polymer electrolytes with negative ions (such as SO3−, and COO−) were used as the doping counter ion;25 although the reported structures exhibited sustained electroactivity, the lack of conductivity and the solubility of the polymer electrolytes in aqueous media lead to subsequent performance degradation. In contrast, the graphitic network structure of graphene provides better structural support and stability (due to its high modulus and strength) and opens the possibility to obtain in situ-generated hybrid nanostructures. In addition, in order to achieve better electrochemical performance, the free movement of the electrons within the structures is also crucial. The complexation of the SG and PANI through the formation of GSO3−PANI+ structure can facilitate easier charge transfer and enhance the conductivity due to the reduce ion intercalation distance.52 Furthermore, the SG-PANI-based biosensor does not exhibit any significant variation in its redox properties during repeated cycling (Figure 9), which highlights the significant long-term stability and preservation of its electrochemical properties.


Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite.

Das G, Yoon HH - Int J Nanomedicine (2015)

Cyclic voltammogram of indium tin oxide/sulfonated graphene/polyaniline/urease at different cycles, obtained at 20 mV·s−1. The arrow in the figure indicates increasing cycle from 1st to the 10th.Abbreviation: vs, versus.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4554425&req=5

f9-ijn-10-055: Cyclic voltammogram of indium tin oxide/sulfonated graphene/polyaniline/urease at different cycles, obtained at 20 mV·s−1. The arrow in the figure indicates increasing cycle from 1st to the 10th.Abbreviation: vs, versus.
Mentions: In most previous instances of urea biosensors, polymer electrolytes with negative ions (such as SO3−, and COO−) were used as the doping counter ion;25 although the reported structures exhibited sustained electroactivity, the lack of conductivity and the solubility of the polymer electrolytes in aqueous media lead to subsequent performance degradation. In contrast, the graphitic network structure of graphene provides better structural support and stability (due to its high modulus and strength) and opens the possibility to obtain in situ-generated hybrid nanostructures. In addition, in order to achieve better electrochemical performance, the free movement of the electrons within the structures is also crucial. The complexation of the SG and PANI through the formation of GSO3−PANI+ structure can facilitate easier charge transfer and enhance the conductivity due to the reduce ion intercalation distance.52 Furthermore, the SG-PANI-based biosensor does not exhibit any significant variation in its redox properties during repeated cycling (Figure 9), which highlights the significant long-term stability and preservation of its electrochemical properties.

Bottom Line: The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds.Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C.The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea.

ABSTRACT
An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm(-2)·mM(-1). The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

No MeSH data available.