Plasmonic properties of silver nanostructures coated with an amorphous silicon-carbon alloy and their applications for sensitive sensing of DNA hybridization.

The use of an amorphous silicon-carbon alloy overcoating on silver nanostructures in a localized surface plasmon resonance (LSPR) sensing platform allows for decreasing the detection limit by an order of magnitude as compared to sensors based on gold nanostructures deposited on glass. In addition, silver based multilayer structures show a distinct plasmonic behaviour as compared to gold based nanostructures, which provides the sensor with an increased short-range sensitivity and a decreased long-range sensitivity.

Localized surface plasmon-enhanced fluorescence spectroscopy for highly-sensitive real-time detection of DNA hybridization.

Versatile and highly-sensitive detection of DNA hybridization is described using metal nanostructures-enhanced fluorescence (MEF) emission intensity when fluorescently-labeled DNA oligomers are covalently immobilized on a nanometer-thin amorphous silicon-carbon layer capping the metal nanostructures. The MEF structures are formed by thermal deposition of silver, gold or silver/gold thin films on glass surfaces and post-annealing at 500 degrees C. The choice of the metal film allows for tuning the optical properties of the interface.

Surface plasmon resonance on gold and silver films coated with thin layers of amorphous silicon-carbon alloys.

The paper reports on a novel surface plasmon resonance (SPR) substrate architecture based on the coating of a gold (Au) or silver (Ag) substrate with 5 nm thin amorphous silicon-carbon alloy films. Ag/a-Si(1-x)C(x):H and Au/a-Si(1-x)C(x):H multilayers are found to provide a significant advantage in terms of sensitivity over both Ag and Au for SPR refractive index sensing. The possibility for the subsequent linking of stable organic monolayers through Si-C bonds is demonstrated.

Amorphous silicon-carbon alloys for efficient localized surface plasmon resonance sensing.

This paper describes a novel platform for preparing localized surface plasmon resonance (LSPR) sensing surfaces. It is based on the coating of gold nanostructures deposited on glass with an amorphous silicon-carbon alloy overcoating. The interest in coating the Au NSs with an amorphous silicon-carbon alloy resides in the possibility of incorporating carboxyl functions directly onto the surface via Si-C covalent bonds.