Ultrathin-film oscillator biosensors excited by ultrafast light pulses.
Novel thin-film oscillator biosensors are developed using picosecond ultrasound method. 100-nm silicon-nitride thin films and 16-nm Pt thin films are used, and ultrashort light pulses are focused on their surfaces to excite the through-thickness resonance vibrations, which are detected by the delayed probe-light pulses using the optoelastic effect. Their fundamental resonance frequencies are 45 and 132 GHz, corresponding to theoretical mass sensitivities of 5.0×10(-5) and 2.2×10(-5) pg/cm(2)/Hz, respectively. These thin-film biosensors are used for detecting human immunoglobulin G (hIgG) with Staphylococcus aureus protein A nonspecifically immobilized on the film surfaces. Injection of a 5 nM analyte caused 2% decrease in the resonance frequency.
Ogi
Hirotsugu
H
Graduate School of Engine Science, Osaka University Machikaneyama 1-3, Toyonaka, Osaka 560-8531, Japan. ogi@me.es.osaka-u.ac.jp
Kawamoto
Tetsuya
T
Nakamura
Nobutomo
N
Hirao
Masahiko
M
Nishiyama
Masayoshi
M
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D008027:Light; D055096:Optical Devices; D055620:Optical Phenomena; D010984:Platinum; D058525:Quartz Crystal Microbalance Techniques; D017655:Silicon Compounds; D013205:Staphylococcal Protein A / Q000032:analysis; D014732:Vibration
D007074:Immunoglobulin G; D017655:Silicon Compounds; D013205:Staphylococcal Protein A; D010984:Platinum; C032734:silicon nitride