Enhanced sensitivity detection of protein immobilization by fluorescent interference on oxidized silicon.
We present a silicon chip-based approach for the enhanced sensitivity detection of surface-immobilized fluorescent molecules. Green fluorescent protein (GFP) is bound to the silicon substrate by a disuccinimidyl terephtalate-aminosilane immobilization procedure. The immobilized organic layers are characterized by surface analysis techniques, like ellipsometry, atomic force microscopy (AFM) and X-ray induced photoelectron spectroscopy. We obtain a 20-fold enhancement of the fluorescent signal, using constructive interference effects in a fused silica dielectric layer, deposited before immobilization onto the silicon. Our method opens perspectives to increase by an order of magnitude the fluorescent response of surface immobilized DNA- or protein-based layers for a variety of biosensor applications.
Volle
J-N
JN
Institute of Microelectronics and Microsystems, Swiss Federal Institute of Technology, CH-1015 Lausanne EPFL, Switzerland.
Chambon
G
G
Sayah
A
A
Reymond
C
C
Fasel
N
N
Gijs
M A M
MA
D000327:Adsorption; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D049452:Green Fluorescent Proteins; D008164:Luminescent Proteins / Q000032:analysis* / Q000737:chemistry* / Q000648:ultrastructure; D008567:Membranes, Artificial; D010084:Oxidation-Reduction; D011506:Proteins / Q000032:analysis / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013499:Surface Properties
D008164:Luminescent Proteins; D008567:Membranes, Artificial; D011506:Proteins; D012821:Silanes; D049452:Green Fluorescent Proteins; D012825:Silicon