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Biosensor for human IgE detection using shear-mode FBAR devices.

Chen YC, Shih WC, Chang WT, Yang CH, Kao KS, Cheng CC - Nanoscale Res Lett (2015)

Bottom Line: The frequency response was measured with an HP8720 network analyzer with a CASCADE probe station.Then, the antigen and antibody were coated on biosensor through their high specificity property.Finally, the shear-mode FBAR device with k t (2) of 3.18% was obtained, and the average sensitivity for human IgE detection of about 1.425 × 10(5) cm(2)/g was achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan.

ABSTRACT
Film bulk acoustic resonators (FBARs) have been evaluated for use as biosensors because of their high sensitivity and small size. This study fabricated a novel human IgE biosensor using shear-mode FBAR devices with c-axis 23°-tilted AlN thin films. Off-axis radio frequency (RF) magnetron sputtering method was used for deposition of c-axis 23°-tilted AlN thin films. The deposition parameters were adopted as working pressure of 5 mTorr, substrate temperature of 300°C, sputtering power of 250 W, and 50 mm distance between off-axis and on-axis. The characteristics of the AlN thin films were investigated by X-ray diffraction and scanning electron microscopy. The frequency response was measured with an HP8720 network analyzer with a CASCADE probe station. The X-ray diffraction revealed (002) preferred wurtzite structure, and the cross-sectional image showed columnar structure with 23°-tilted AlN thin films. In the biosensor, an Au/Cr layer in the FBAR backside cavity was used as the detection layer and the Au surface was modified using self-assembly monolayers (SAMs) method. Then, the antigen and antibody were coated on biosensor through their high specificity property. Finally, the shear-mode FBAR device with k t (2) of 3.18% was obtained, and the average sensitivity for human IgE detection of about 1.425 × 10(5) cm(2)/g was achieved.

No MeSH data available.


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Theθ-2θX-ray scans of the AlN thin film.
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Fig5: Theθ-2θX-ray scans of the AlN thin film.

Mentions: A highly c-axis orientation is the ideal piezoelectric property of a FBAR device. According to the literature, a 34.5° c-axis tilted piezoelectric thin film in FBAR device exits strongly shear-mode transmittance [25]. The optimized sputtering conditions for 23° c-axis tilted highly textured AlN thin films were obtained in our previous report [26], those were working pressure of 5 mTorr, substrate temperature of 300°C, sputtering power of 250 W, and the off-axis of 50 mm. Figure 5 shows the c-axis preferred orientation of AlN thin films with small full width at half maximum (FWHM). Besides, Figure 6 shows the cross-sectional images, which reveal columnar with 23°-tilted AlN thin films.Figure 5


Biosensor for human IgE detection using shear-mode FBAR devices.

Chen YC, Shih WC, Chang WT, Yang CH, Kao KS, Cheng CC - Nanoscale Res Lett (2015)

Theθ-2θX-ray scans of the AlN thin film.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385051&req=5

Fig5: Theθ-2θX-ray scans of the AlN thin film.
Mentions: A highly c-axis orientation is the ideal piezoelectric property of a FBAR device. According to the literature, a 34.5° c-axis tilted piezoelectric thin film in FBAR device exits strongly shear-mode transmittance [25]. The optimized sputtering conditions for 23° c-axis tilted highly textured AlN thin films were obtained in our previous report [26], those were working pressure of 5 mTorr, substrate temperature of 300°C, sputtering power of 250 W, and the off-axis of 50 mm. Figure 5 shows the c-axis preferred orientation of AlN thin films with small full width at half maximum (FWHM). Besides, Figure 6 shows the cross-sectional images, which reveal columnar with 23°-tilted AlN thin films.Figure 5

Bottom Line: The frequency response was measured with an HP8720 network analyzer with a CASCADE probe station.Then, the antigen and antibody were coated on biosensor through their high specificity property.Finally, the shear-mode FBAR device with k t (2) of 3.18% was obtained, and the average sensitivity for human IgE detection of about 1.425 × 10(5) cm(2)/g was achieved.

View Article: PubMed Central - PubMed

Affiliation: Department of Electrical Engineering, National Sun Yat-Sen University, Kaohsiung, 80424 Taiwan.

ABSTRACT
Film bulk acoustic resonators (FBARs) have been evaluated for use as biosensors because of their high sensitivity and small size. This study fabricated a novel human IgE biosensor using shear-mode FBAR devices with c-axis 23°-tilted AlN thin films. Off-axis radio frequency (RF) magnetron sputtering method was used for deposition of c-axis 23°-tilted AlN thin films. The deposition parameters were adopted as working pressure of 5 mTorr, substrate temperature of 300°C, sputtering power of 250 W, and 50 mm distance between off-axis and on-axis. The characteristics of the AlN thin films were investigated by X-ray diffraction and scanning electron microscopy. The frequency response was measured with an HP8720 network analyzer with a CASCADE probe station. The X-ray diffraction revealed (002) preferred wurtzite structure, and the cross-sectional image showed columnar structure with 23°-tilted AlN thin films. In the biosensor, an Au/Cr layer in the FBAR backside cavity was used as the detection layer and the Au surface was modified using self-assembly monolayers (SAMs) method. Then, the antigen and antibody were coated on biosensor through their high specificity property. Finally, the shear-mode FBAR device with k t (2) of 3.18% was obtained, and the average sensitivity for human IgE detection of about 1.425 × 10(5) cm(2)/g was achieved.

No MeSH data available.


Related in: MedlinePlus