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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.


Fourier-transform infrared spectra.Notes: (a) graphene oxide; (b) sulfonated graphene oxide; and (c) sulfonated graphene/polyaniline.
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f5-ijn-10-055: Fourier-transform infrared spectra.Notes: (a) graphene oxide; (b) sulfonated graphene oxide; and (c) sulfonated graphene/polyaniline.

Mentions: The FTIR spectra of the prepared GO, SGO, and SG-PANI are shown in Figure 5. The spectrum of GO reveals the presence of −C=O (νC=O at 1,727 cm−1), C–O–C (νC–O–C at 1,225 cm−1), and C–O (νC=O at 1,050 cm−1) functional groups.34 The band observed at 1,620 cm−1 was due to the unoxidized graphitic domains. Sulfonation resulted in the attenuation of the bands at 1,620, 1,225, and 1,050 cm−1 in the spectrum of SGO. The appearance of band at 1,030 cm−1 (νS=O) confirms the presence of SO3− group.35 Compared to SGO, several new bands were detected in the spectrum of SG-PANI, such as the stretching vibrational bands corresponding to C=C groups in the quinoid (νC=C at 1,577 cm−1) and benzoid (νC=C at 1,493 cm−1) moiety. The characteristics C–N stretching vibration νC–N at 1,300 cm−1) and C–H in-plane bending vibration at 1,142 cm−1 were also visible in the spectrum of SG-PANI.34 The observation of C=C stretching vibrations corresponding to the quinoid and benzoid rings in SG-PANI suggests a greater degree of conjugation, originating from the ordered structure of PANI nanofibers, as well as from the doping effect of the –SO3H groups of SG on PANI.3435 The intensity of the C=O stretching band was observed to decrease in the spectrum of SG-PANI, indicating the reduction of SGO during the electrochemical oxidative polymerization.


Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite.

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

Fourier-transform infrared spectra.Notes: (a) graphene oxide; (b) sulfonated graphene oxide; and (c) sulfonated graphene/polyaniline.
© Copyright Policy
Related In: Results  -  Collection

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f5-ijn-10-055: Fourier-transform infrared spectra.Notes: (a) graphene oxide; (b) sulfonated graphene oxide; and (c) sulfonated graphene/polyaniline.
Mentions: The FTIR spectra of the prepared GO, SGO, and SG-PANI are shown in Figure 5. The spectrum of GO reveals the presence of −C=O (νC=O at 1,727 cm−1), C–O–C (νC–O–C at 1,225 cm−1), and C–O (νC=O at 1,050 cm−1) functional groups.34 The band observed at 1,620 cm−1 was due to the unoxidized graphitic domains. Sulfonation resulted in the attenuation of the bands at 1,620, 1,225, and 1,050 cm−1 in the spectrum of SGO. The appearance of band at 1,030 cm−1 (νS=O) confirms the presence of SO3− group.35 Compared to SGO, several new bands were detected in the spectrum of SG-PANI, such as the stretching vibrational bands corresponding to C=C groups in the quinoid (νC=C at 1,577 cm−1) and benzoid (νC=C at 1,493 cm−1) moiety. The characteristics C–N stretching vibration νC–N at 1,300 cm−1) and C–H in-plane bending vibration at 1,142 cm−1 were also visible in the spectrum of SG-PANI.34 The observation of C=C stretching vibrations corresponding to the quinoid and benzoid rings in SG-PANI suggests a greater degree of conjugation, originating from the ordered structure of PANI nanofibers, as well as from the doping effect of the –SO3H groups of SG on PANI.3435 The intensity of the C=O stretching band was observed to decrease in the spectrum of SG-PANI, indicating the reduction of SGO during the electrochemical oxidative polymerization.

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.