ABSTRACT
The nanosensors' platform made of a stimuli-responsive polymer/noble metal nanoparticle composite thin film exploits the combination of the swelling-shrinking transition in a poly(N,N'-dimethylaminoethyl methacrylate) brush and the localized surface plasmon resonance in metal nanoparticles to enable the transduction of changes in the solution pH in the near-physiological range into a pronounced optical signal.
Subject(s)
Biosensing Techniques/methods , Methacrylates/chemistry , Nanostructures/chemistry , Nanotechnology/methods , Nylons/chemistry , Surface Plasmon Resonance/methods , Glucose/chemistry , Hydrogen-Ion ConcentrationABSTRACT
Localized surface plasmon resonance excited in gold nanoparticles coupled with a responsive polymer gel is explored. A specially designed structure (vertically aligned cylindrical pores decorated with gold nanoparticles) of responsive polymer gel thin films allows for the transduction of external signal/ stimuli into a strong optical effect enhanced by interactions of gold nanoparticles.
ABSTRACT
An ultrathin novel nanosensor (31.5 +/- 4.1 nm thick in the absence of analytes), employing a molecularly imprinted polymer as a recognition element for cholesterol and gold nanoparticle enhanced transmission surface plasmon resonance spectroscopy for detection, was constructed.
ABSTRACT
Swelling (and shrinking) of poly(2-vinylpyridine), P2VP, polymer brushes, caused by pH changes, could be readily monitored by transmission surface plasmon resonance, T-SPR, spectroscopy. Gold nanoparticles attached to the P2VP polymer brushes dramatically enhanced the pH-induced shift in the T-SPR absorption spectra. (A 50 nm shift of the absorption maximum of the T-SPR spectrum of the supporting gold nanoislands was observed upon changing the pH from 5.0 to 2.0, corresponding to a swelling of the polymer brushes from 8.1 +/- 0.7 to 24.0 +/- 2.0 nm. Same shift in the opposite direction was observed upon changing the pH from 2.0 to 5.0.)
ABSTRACT
Functionalization of silver and gold nanoparticles by 12mer-thiolated homo-oligonucleotides, SA and ST (containing only adenine or thymine, respectively), and their hybridization and dehybridization in aqueous dispersions have been described. In addition, ST and SA were self-assembled onto gold films and hybridized with their complementary pairs, unlabeled or labeled by gold and silver nanoparticles. The base pairing between DNA strands and the types of oligonucleotides (adenine or thymine) attached to the nanoparticles was detected by Polarization Modulated Fourier Transform Infrared Reflection Absorption Spectroscopy (PM-FTIRRAS).
