Ultrathin-film oscillator biosensors excited by ultrafast light pulses

• Published in: Biosensors & bioelectronics Vol. 26; no. 4; pp. 1273 - 1277
• Main Authors: Ogi, Hirotsugu, Kawamoto, Tetsuya, Nakamura, Nobutomo, Hirao, Masahiko, Nishiyama, Masayoshi
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier B.V 15-12-2010; Elsevier
• Subjects: Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Film oscillator; Fundamental and applied biological sciences. Psychology; Humans; Immunoglobulin G - analysis; Immunosensor; Light; Mass sensitivity; Methods. Procedures. Technologies; Optical Devices; Optical Phenomena; Picosecond ultrasound; Platinum; Quartz Crystal Microbalance Techniques; Silicon Compounds; Staphylococcal Protein A - analysis; Staphylococcus aureus; Various methods and equipments; Vibration; Mass sensitivity; Picosecond ultrasound; Film oscillator; Immunosensor; Sensitivity; Biosensor; Light; Ultrasound
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2010.06.074

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.