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Detection of formaldehyde in water: a shape-effect on the plasmonic sensing properties of the gold nanoparticles.

Nengsih S, Umar AA, Salleh MM, Oyama M - Sensors (Basel) (2012)

Bottom Line: In typical results, it was found that the plasmonic properties of gold nanostructures were very sensitive to the presence of formaldehyde in their surrounding medium by showing the change in both the plasmonic peaks position and the intensity.However, in the present study, effective plasmonic peak shift was not observed due to the intense plasmonic coupling of closely packed nanorod structures on the surface.Nevertheless, the present results at least provide a potential strategy for response enhancement via shape-effects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microengineering and Nanoelectronic (IMEN), Universiti Kebangsaan Malaysia, UKM Bangi 43600, Selangor, Malaysia. sri_nengsih85@yahoo.com

ABSTRACT
The effect of morphology on the plasmonic sensing of the presence of formaldehyde in water by gold nanostructures has been investigated. The gold nanostructures with two different morphologies, namely spherical and rod, were prepared using a seed-mediated method. In typical results, it was found that the plasmonic properties of gold nanostructures were very sensitive to the presence of formaldehyde in their surrounding medium by showing the change in both the plasmonic peaks position and the intensity. Spherical nanoparticles (GNS), for example, indicated an increase in the sensitivity when the size was increased from 25 to 35 nm and dramatically decreased when the size was further increased. An m value, the ratio between plasmonic peak shift and refractive index change, as high as 36.5 nm/RIU (refractive index unit) was obtained so far. An expanded sensing mode to FD was obtained when gold nanostructures with nanorods morphology (GNR) were used because of the presence of two plasmonic modes for response probing. However, in the present study, effective plasmonic peak shift was not observed due to the intense plasmonic coupling of closely packed nanorod structures on the surface. Nevertheless, the present results at least provide a potential strategy for response enhancement via shape-effects. High performance plasmonic sensors could be obtained if controlled arrays of nanorods can be prepared on the surface.

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(A and B) FESEM images of spherical gold nanoparticles that were grown on the surface for 2 h in the growth solution; (C) The optical absorption spectrum of gold nanoparticles on the surface that was grown for different growth time, namely (a) 0.5; (b) 1; (c) 2; (d) 4; (e) 8 and (f) 16 h. Scale bars in A and B are 100 nm.
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f2-sensors-12-10309: (A and B) FESEM images of spherical gold nanoparticles that were grown on the surface for 2 h in the growth solution; (C) The optical absorption spectrum of gold nanoparticles on the surface that was grown for different growth time, namely (a) 0.5; (b) 1; (c) 2; (d) 4; (e) 8 and (f) 16 h. Scale bars in A and B are 100 nm.

Mentions: We have effectively prepared gold nanoparticles with two different morphologies in this work, namely spherical and nanorods, using the approaches which are described in the Experimental section. The FESEM image and their related absorption spectra are shown in Figures 2–4.


Detection of formaldehyde in water: a shape-effect on the plasmonic sensing properties of the gold nanoparticles.

Nengsih S, Umar AA, Salleh MM, Oyama M - Sensors (Basel) (2012)

(A and B) FESEM images of spherical gold nanoparticles that were grown on the surface for 2 h in the growth solution; (C) The optical absorption spectrum of gold nanoparticles on the surface that was grown for different growth time, namely (a) 0.5; (b) 1; (c) 2; (d) 4; (e) 8 and (f) 16 h. Scale bars in A and B are 100 nm.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3472829&req=5

f2-sensors-12-10309: (A and B) FESEM images of spherical gold nanoparticles that were grown on the surface for 2 h in the growth solution; (C) The optical absorption spectrum of gold nanoparticles on the surface that was grown for different growth time, namely (a) 0.5; (b) 1; (c) 2; (d) 4; (e) 8 and (f) 16 h. Scale bars in A and B are 100 nm.
Mentions: We have effectively prepared gold nanoparticles with two different morphologies in this work, namely spherical and nanorods, using the approaches which are described in the Experimental section. The FESEM image and their related absorption spectra are shown in Figures 2–4.

Bottom Line: In typical results, it was found that the plasmonic properties of gold nanostructures were very sensitive to the presence of formaldehyde in their surrounding medium by showing the change in both the plasmonic peaks position and the intensity.However, in the present study, effective plasmonic peak shift was not observed due to the intense plasmonic coupling of closely packed nanorod structures on the surface.Nevertheless, the present results at least provide a potential strategy for response enhancement via shape-effects.

View Article: PubMed Central - PubMed

Affiliation: Institute of Microengineering and Nanoelectronic (IMEN), Universiti Kebangsaan Malaysia, UKM Bangi 43600, Selangor, Malaysia. sri_nengsih85@yahoo.com

ABSTRACT
The effect of morphology on the plasmonic sensing of the presence of formaldehyde in water by gold nanostructures has been investigated. The gold nanostructures with two different morphologies, namely spherical and rod, were prepared using a seed-mediated method. In typical results, it was found that the plasmonic properties of gold nanostructures were very sensitive to the presence of formaldehyde in their surrounding medium by showing the change in both the plasmonic peaks position and the intensity. Spherical nanoparticles (GNS), for example, indicated an increase in the sensitivity when the size was increased from 25 to 35 nm and dramatically decreased when the size was further increased. An m value, the ratio between plasmonic peak shift and refractive index change, as high as 36.5 nm/RIU (refractive index unit) was obtained so far. An expanded sensing mode to FD was obtained when gold nanostructures with nanorods morphology (GNR) were used because of the presence of two plasmonic modes for response probing. However, in the present study, effective plasmonic peak shift was not observed due to the intense plasmonic coupling of closely packed nanorod structures on the surface. Nevertheless, the present results at least provide a potential strategy for response enhancement via shape-effects. High performance plasmonic sensors could be obtained if controlled arrays of nanorods can be prepared on the surface.

Show MeSH