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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.


Related in: MedlinePlus

The frequency response of a FBAR device in air and liquid environment.
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Fig8: The frequency response of a FBAR device in air and liquid environment.

Mentions: Besides, the analysis methods were used for biosensor in liquid and tiny mass detection in air through the shear mode and longitudinal mode, respectively. Figure 8 shows the frequency response of FBAR device in air and liquid environment. The longitudinal mode almost disappeared in liquid environment because of the decrease of quality factor (Q) which reduces the mass resolution substantially, whereas the shear mode maintains high readability. However, the literatures mentioned that the large reflection coefficient of longitudinal mode in solid and liquid interface which is the key factor result in the acoustic wave vanished. Therefore, the shear mode propagating in solid medium maintains its movement through a liquid environment [33-35]. The experimental and analytical results indicate that the longitudinal mode is the key indicator to identify the sensing environment, and the shear mode can be exploited in biosensor applications. Hence, FBAR devices with 23°-tilted AlN thin films are suitable for human IgE detection.Figure 8


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)

The frequency response of a FBAR device in air and liquid environment.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig8: The frequency response of a FBAR device in air and liquid environment.
Mentions: Besides, the analysis methods were used for biosensor in liquid and tiny mass detection in air through the shear mode and longitudinal mode, respectively. Figure 8 shows the frequency response of FBAR device in air and liquid environment. The longitudinal mode almost disappeared in liquid environment because of the decrease of quality factor (Q) which reduces the mass resolution substantially, whereas the shear mode maintains high readability. However, the literatures mentioned that the large reflection coefficient of longitudinal mode in solid and liquid interface which is the key factor result in the acoustic wave vanished. Therefore, the shear mode propagating in solid medium maintains its movement through a liquid environment [33-35]. The experimental and analytical results indicate that the longitudinal mode is the key indicator to identify the sensing environment, and the shear mode can be exploited in biosensor applications. Hence, FBAR devices with 23°-tilted AlN thin films are suitable for human IgE detection.Figure 8

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