Multi-layered plasma-polymerized chips for SPR-based detection.
The surface functionalization of a noble metal is crucial in a surface plasmon resonance-based biomolecular detection system because the interfacial coating must retain the activity of immobilized biomolecules while enhancing the optimal loading. We present here a one-step, room-temperature, high-speed, gas-phase plasma polymerization process for functionalizing gold substrates using siloxane as an adhesion layer and acrylic acid as a functional layer. Siloxane- and thiol-based coatings were compared for their performance as adhesion and the interfacial layer for subsequent functionalization. An in situ sequential deposition of siloxane and acrylic acid resulted in a 7-fold increase in carboxylic functionality surfacial content compared to films deposited with thiol-containing precursors. Grading of the layer composition achieved as a consequence of ion-induced mixing on the surface coating under the application of the plasma is confirmed through secondary ion mass spectroscopic studies. DNA hybridization assays were demonstrated on gold/glass substrates using surface plasmon enhanced ellipsometry and the applicability of this coating for protein immunoassays were demonstrated with plasma functionalized gold/plastic substrates in Biacore 3000 SPR instrument.
Biomedical Diagnostics Institute (BDI), Dublin City University, Glasnevin, Dublin-9, Ireland. ramprasad.gandhiraman@dcu.ie
Ram P
RP
Gandhiraman
Nam Cao Hoai
NC
Le
Chandra K
CK
Dixit
Cedric
C
Volcke
Colin
C
Doyle
Vladimir
V
Gubala
Suresh
S
Uppal
Ruairi
R
Monaghan
Bryony
B
James
Richard
R
O'Kennedy
Stephen
S
Daniels
David E
DE
Williams
D001681:Biological Assay / Q000295:instrumentation*; D004247:DNA / Q000737:chemistry; D004595:Electroplating; D006046:Gold / Q000737:chemistry; D058105:Polymerization; D020349:Surface Plasmon Resonance / Q000295:instrumentation
D006046:Gold; D004247:DNA