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Sol-Gel Thin Films for Plasmonic Gas Sensors.

Della Gaspera E, Martucci A - Sensors (Basel) (2015)

Bottom Line: Plasmonic gas sensors are optical sensors that use localized surface plasmons or extended surface plasmons as transducing platform.Surface plasmons are very sensitive to dielectric variations of the environment or to electron exchange, and these effects have been exploited for the realization of sensitive gas sensors.In this paper, we review our research work of the last few years on the synthesis and the gas sensing properties of sol-gel based nanomaterials for plasmonic sensors.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168, Australia. enrico.dellagaspera@csiro.au.

ABSTRACT
Plasmonic gas sensors are optical sensors that use localized surface plasmons or extended surface plasmons as transducing platform. Surface plasmons are very sensitive to dielectric variations of the environment or to electron exchange, and these effects have been exploited for the realization of sensitive gas sensors. In this paper, we review our research work of the last few years on the synthesis and the gas sensing properties of sol-gel based nanomaterials for plasmonic sensors.

No MeSH data available.


Related in: MedlinePlus

(a) Optical absorption spectra of a NiTiO3-Au film exposed to air and to 100 ppm H2S at 350 °C. The blue dotted plot (right vertical axis) shows the variation in absorbance as a function of the wavelength; (b) Time resolved tests for a NiTiO3-Au film showing the better response to H2S (100 ppm) and the absence of cross sensitivity to CO (1%) and H2 (1%) when compared to TiO2-Au film (T = 350 °C, λ = 605 nm); (c) Time resolved tests for a NiTiO3-Au film exposed to 100 ppm H2S showing the variation in recovery times as a function of the operating temperature (λ = 605 nm); (d) Oscillatory behavior of a NiTiO3-Au film exposed to 100 ppm H2S (T = 350 °C, λ = 590nm). The inset shows a zoomed view of a few oscillations.
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sensors-15-16910-f002: (a) Optical absorption spectra of a NiTiO3-Au film exposed to air and to 100 ppm H2S at 350 °C. The blue dotted plot (right vertical axis) shows the variation in absorbance as a function of the wavelength; (b) Time resolved tests for a NiTiO3-Au film showing the better response to H2S (100 ppm) and the absence of cross sensitivity to CO (1%) and H2 (1%) when compared to TiO2-Au film (T = 350 °C, λ = 605 nm); (c) Time resolved tests for a NiTiO3-Au film exposed to 100 ppm H2S showing the variation in recovery times as a function of the operating temperature (λ = 605 nm); (d) Oscillatory behavior of a NiTiO3-Au film exposed to 100 ppm H2S (T = 350 °C, λ = 590nm). The inset shows a zoomed view of a few oscillations.

Mentions: This evidence suggests an active role of the oxide matrix in reacting with the target gas, while Au nanoparticles act as optical probes enabling optical detection. As shown in Figure 2a, a strong variation in optical absorption around the Au SPR peak is observed after exposing the sensing materials to H2S: the plasmon peak of Au is broadened and damped in the presence of hydrogen sulfide, suggesting a direct electronic interaction between sulfur and the free electrons at the surface of Au NPs. Minimal or no cross sensitivity towards interfering gases such as CO and H2 has been proved, especially after a careful selection of the operative wavelength used for the time-resolved tests. Moreover, increased selectivity for other reducing gases such as CO and H2 is achieved with respect to TiO2-Au nanocomposites. (Figure 2b). Such materials demonstrated very high sensitivity to H2S with detection limits below 10 ppm at operative temperatures between 300 and 350 °C, and very fast response times, of the order of 10–20 s. However, the recovery times are strongly affected by the temperature, as a consequence of the thermally activated desorption of sulfur species from the nanocomposite material. Given that the baseline is recovered in all tests performed above 300 °C (Figure 2c), we can conclude that the process is kinetically limited by such a desorption process.


Sol-Gel Thin Films for Plasmonic Gas Sensors.

Della Gaspera E, Martucci A - Sensors (Basel) (2015)

(a) Optical absorption spectra of a NiTiO3-Au film exposed to air and to 100 ppm H2S at 350 °C. The blue dotted plot (right vertical axis) shows the variation in absorbance as a function of the wavelength; (b) Time resolved tests for a NiTiO3-Au film showing the better response to H2S (100 ppm) and the absence of cross sensitivity to CO (1%) and H2 (1%) when compared to TiO2-Au film (T = 350 °C, λ = 605 nm); (c) Time resolved tests for a NiTiO3-Au film exposed to 100 ppm H2S showing the variation in recovery times as a function of the operating temperature (λ = 605 nm); (d) Oscillatory behavior of a NiTiO3-Au film exposed to 100 ppm H2S (T = 350 °C, λ = 590nm). The inset shows a zoomed view of a few oscillations.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541914&req=5

sensors-15-16910-f002: (a) Optical absorption spectra of a NiTiO3-Au film exposed to air and to 100 ppm H2S at 350 °C. The blue dotted plot (right vertical axis) shows the variation in absorbance as a function of the wavelength; (b) Time resolved tests for a NiTiO3-Au film showing the better response to H2S (100 ppm) and the absence of cross sensitivity to CO (1%) and H2 (1%) when compared to TiO2-Au film (T = 350 °C, λ = 605 nm); (c) Time resolved tests for a NiTiO3-Au film exposed to 100 ppm H2S showing the variation in recovery times as a function of the operating temperature (λ = 605 nm); (d) Oscillatory behavior of a NiTiO3-Au film exposed to 100 ppm H2S (T = 350 °C, λ = 590nm). The inset shows a zoomed view of a few oscillations.
Mentions: This evidence suggests an active role of the oxide matrix in reacting with the target gas, while Au nanoparticles act as optical probes enabling optical detection. As shown in Figure 2a, a strong variation in optical absorption around the Au SPR peak is observed after exposing the sensing materials to H2S: the plasmon peak of Au is broadened and damped in the presence of hydrogen sulfide, suggesting a direct electronic interaction between sulfur and the free electrons at the surface of Au NPs. Minimal or no cross sensitivity towards interfering gases such as CO and H2 has been proved, especially after a careful selection of the operative wavelength used for the time-resolved tests. Moreover, increased selectivity for other reducing gases such as CO and H2 is achieved with respect to TiO2-Au nanocomposites. (Figure 2b). Such materials demonstrated very high sensitivity to H2S with detection limits below 10 ppm at operative temperatures between 300 and 350 °C, and very fast response times, of the order of 10–20 s. However, the recovery times are strongly affected by the temperature, as a consequence of the thermally activated desorption of sulfur species from the nanocomposite material. Given that the baseline is recovered in all tests performed above 300 °C (Figure 2c), we can conclude that the process is kinetically limited by such a desorption process.

Bottom Line: Plasmonic gas sensors are optical sensors that use localized surface plasmons or extended surface plasmons as transducing platform.Surface plasmons are very sensitive to dielectric variations of the environment or to electron exchange, and these effects have been exploited for the realization of sensitive gas sensors.In this paper, we review our research work of the last few years on the synthesis and the gas sensing properties of sol-gel based nanomaterials for plasmonic sensors.

View Article: PubMed Central - PubMed

Affiliation: CSIRO Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168, Australia. enrico.dellagaspera@csiro.au.

ABSTRACT
Plasmonic gas sensors are optical sensors that use localized surface plasmons or extended surface plasmons as transducing platform. Surface plasmons are very sensitive to dielectric variations of the environment or to electron exchange, and these effects have been exploited for the realization of sensitive gas sensors. In this paper, we review our research work of the last few years on the synthesis and the gas sensing properties of sol-gel based nanomaterials for plasmonic sensors.

No MeSH data available.


Related in: MedlinePlus