A miniaturized germanium-doped silicon dioxide-based surface plasmon resonance waveguide sensor for immunoassay detection.
A surface plasmon resonance (SPR) waveguide immunosensor fabricated by germanium-doped silicon dioxide was investigated in this study. The designed waveguide sensor consisted of a 10 microm SiO(2) substrate layer (n=1.469), a 10 microm Ge-SiO(2) channel guide (n=1.492) and a 50 nm gold film layer for immobilization of biomolecules and SPR signal detection. The resultant spectral signal was measured by a portable spectrophotometer, where the sensor was aligned by a custom-designed micro-positioner. The results of the glycerol calibration standards showed that the resonance wavelength shifted from 628 to 758 nm due to changes of refractive index from 1.36 to 1.418. Flow-through immunoassay on waveguide sensors also showed the interactions of protein A, monoclonal antibody (mAb ALV-J) and avian leucosis virus (ALVs) resulted in wavelength shifting of 4.17, 3.03 and 2.18 nm, respectively. The SPR dynamic interaction could also be demonstrated successfully in 4 min as the sensor was integrated with a lateral flow nitrocellulose strip. These results suggest that SPR detection could be carried out on designed waveguide sensor, and the integration of nitrocellulose strip for sample filtering and fluid carrier would facilitate applications in point-of-care portable system.
Huang
Jhen-Gang
JG
Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan.
Lee
Chen-Lung
CL
Lin
Hsueh-Min
HM
Chuang
Tsung-Liang
TL
Wang
Way-Seen
WS
Juang
Rong-Huey
RH
Wang
Ching-Ho
CH
Lee
Chih Kung
CK
Lin
Shi-Ming
SM
Lin
Chii-Wann
CW
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D003101:Collodion / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D005857:Germanium / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization; D012822:Silicon Dioxide / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods; D013499:Surface Properties
D005857:Germanium; D012822:Silicon Dioxide; D003101:Collodion