Limits...
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.

Show MeSH
Absorption spectra of GNS in the presence of several concentration of FD. The absorbance of the GNS increase and the plasmonic peaks red-shift with the increasing of the FD concentration.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3472829&req=5

f5-sensors-12-10309: Absorption spectra of GNS in the presence of several concentration of FD. The absorbance of the GNS increase and the plasmonic peaks red-shift with the increasing of the FD concentration.

Mentions: We further examined the plasmonic response of the GNS to the presence of several concentrations of FD. The results are shown in Figure 5. As revealed in Figure 4, the optical absorption of the GNS gradually modified upon the increase of FD concentration that indicated by effective increase in the absorbance as well as red-shifting in the plasmonic peaks as the increasing of FD concentration. From the spectra, it can be found that the introduction of FD at concentrations as low as 3% has effectively changed both the intensity of the absorbance and the plasmonic peaks' position (red-shift). This change was found to further improve with the increase in FD concentration up to 37% (also called 100% formalin), reflecting excellent response linearity.


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)

Absorption spectra of GNS in the presence of several concentration of FD. The absorbance of the GNS increase and the plasmonic peaks red-shift with the increasing of the FD concentration.
© Copyright Policy
Related In: Results  -  Collection

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

f5-sensors-12-10309: Absorption spectra of GNS in the presence of several concentration of FD. The absorbance of the GNS increase and the plasmonic peaks red-shift with the increasing of the FD concentration.
Mentions: We further examined the plasmonic response of the GNS to the presence of several concentrations of FD. The results are shown in Figure 5. As revealed in Figure 4, the optical absorption of the GNS gradually modified upon the increase of FD concentration that indicated by effective increase in the absorbance as well as red-shifting in the plasmonic peaks as the increasing of FD concentration. From the spectra, it can be found that the introduction of FD at concentrations as low as 3% has effectively changed both the intensity of the absorbance and the plasmonic peaks' position (red-shift). This change was found to further improve with the increase in FD concentration up to 37% (also called 100% formalin), reflecting excellent response linearity.

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