Influence of the metal film thickness on the sensitivity of surface plasmon resonance biosensors.
The influence of the metal film thickness (i.e., the chromium adhesion promoting film and the gold film) on the sensitivity of surface plasmon resonance (SPR) signals (i.e., resonance angle shift and reflectance change) towards the thickness variation of the nonabsorbing dielectric film is investigated. The sensitivity of reflectance change decreases when a thick chromium film or a thin gold film is employed. Its linear range becomes narrower as the thickness of the metal films increases. The sensitivity and linear range of the resonance angle shift are not affected by the thickness variation of the metal films. The phenomena were theoretically explained based on the attenuated total reflection (ATR) generated evanescent field at the prism/metal interface and the SPR-generated evanescent field at the metal/dielectric interface.
Ekgasit
Sanong
S
Sensor Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. sanong.e@chula.ac.th
Thammacharoen
Chuchaat
C
Yu
Fang
F
Knoll
Wolfgang
W
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D002857:Chromium / Q000737:chemistry*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D008670:Metals / Q000737:chemistry; D008968:Molecular Conformation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*
D008567:Membranes, Artificial; D008670:Metals; D002857:Chromium; D006046:Gold