TY  - JOUR
A1  - Weiler, Markus
A1  - Menzel, Christoph
A1  - Pertsch, Thomas
A1  - Alaee, Rasoul
A1  - Rockstuhl, Carsten
A1  - Pacholski, Claudia
T1  - Bottom-Up Fabrication of Hybrid Plasmonic Sensors: Gold-Capped Hydrogel Microspheres Embedded in Periodic Metal Hole Arrays
JF  - Polymer : the international journal for the science and technology of polymers
N2  - The high potential of bottom-up fabrication strategies for realizing sophisticated optical sensors combining the high sensitivity of a surface plasmon resonance with the exceptional properties of stimuli-responsive hydrogel is demonstrated. The sensor is composed of a periodic hole array in a gold film whose holes are filled with gold-capped poly(N-isoproyl-acrylamide) (polyNIPAM) microspheres. The production of this sensor relies on a pure chemical approach enabling simple, time-efficient, and cost-efficient preparation of sensor platforms covering areas of cm(2). The transmission spectrum of this plasmonic sensor shows a strong interaction between propagating surface plasmon polaritons at the metal film surface and localized surface plasmon resonance of the gold cap on top of the polyNIPAM microspheres. Computer simulations support this experimental observation. These interactions lead to distinct changes in the transmission spectrum, which allow for the simultaneous, sensitive optical detection of refractive index changes in the surrounding medium and the swelling state of the embedded polyNIPAM microsphere under the gold cap. The volume of the polyNIPAM microsphere located underneath the gold cap can be changed by certain stimuli such as temperature, pH, ionic strength, and distinct molecules bound to the hydrogel matrix facilitating the detection of analytes which do not change the refractive index of the surrounding medium significantly.
KW  - bottom-up
KW  - hydrogel
KW  - hole array
KW  - sensor
KW  - surface plasmon resonance
Y1  - 2016
U6  - https://doi.org/10.1021/acsami.6b08636
SN  - 1944-8244
VL  - 8
SP  - 26392
EP  - 26399
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Stanglmair, Christoph
A1  - Neubrech, Frank
A1  - Pacholski, Claudia
T1  - Chemical routes to surface enhanced infrared absorption (SEIRA) substrates
JF  - Zeitschrift für physikalische Chemie : international journal of research in physical chemistry and chemical physics
N2  - Bottom-up strategies for fabricating SEIRA substrates are presented. For this purpose, wet-chemically prepared gold nanoparticles are coated with a polystyrene shell and subsequently self-assembled into different nanostructures such as quasi-hexagonally ordered gold nanoparticle monolayers, double layers, and honeycomb structures. Furthermore elongated gold nanostructures are obtained by sintering of gold nanoparticle double layers. The optical properties of these different gold nanostructures are directly connected to their morphology and geometrical arrangement - leading to surface plasmon resonances from the visible to the infrared wavelength range. Finally, SEIRA enhancement factors are determined. Gold nanoparticle double layers show the best performance as SEIRA substrates.
KW  - bottom-up
KW  - gold nanoparticles
KW  - self-assembly
KW  - surface enhanced spectroscopy
Y1  - 2018
U6  - https://doi.org/10.1515/zpch-2018-1132
SN  - 0942-9352
VL  - 232
IS  - 9-11
SP  - 1527
EP  - 1539
PB  - De Gruyter
CY  - Berlin
ER  -