TY  - JOUR
A1  - Pacholski, Claudia
A1  - Rosencrantz, Sophia
A1  - Rosencrantz, Ruben R.
A1  - Balderas-Valadez, Ruth Fabiola
T1  - Plasmonic biosensors fabricated by galvanic displacement reactions for monitoring biomolecular interactions in real time
JF  - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica
N2  - Optical sensors are prepared by reduction of gold ions using freshly etched hydride-terminated porous silicon, and their ability to specifically detect binding between protein A/rabbit IgG and asialofetuin/Erythrina cristagalli lectin is studied. The fabrication process is simple, fast, and reproducible, and does not require complicated lab equipment. The resulting nanostructured gold layer on silicon shows an optical response in the visible range based on the excitation of localized surface plasmon resonance. Variations in the refractive index of the surrounding medium result in a color change of the sensor which can be observed by the naked eye. By monitoring the spectral position of the localized surface plasmon resonance using reflectance spectroscopy, a bulk sensitivity of 296 nm +/- 3 nm/RIU is determined. Furthermore, selectivity to target analytes is conferred to the sensor through functionalization of its surface with appropriate capture probes. For this purpose, biomolecules are deposited either by physical adsorption or by covalent coupling. Both strategies are successfully tested, i.e., the optical response of the sensor is dependent on the concentration of respective target analyte in the solution facilitating the determination of equilibrium dissociation constants for protein A/rabbit IgG as well as asialofetuin/Erythrina cristagalli lectin which are in accordance with reported values in literature. These results demonstrate the potential of the developed optical sensor for cost-efficient biosensor applications.
KW  - Optical sensor
KW  - Gold nanostructure
KW  - Localized surface plasmon resonance
KW  - Surface functionalization
KW  - Biomolecular interactions
KW  - Lectin
Y1  - 2020
U6  - https://doi.org/10.1007/s00216-020-02414-0
SN  - 1618-2642
SN  - 1618-2650
VL  - 412
IS  - 14
SP  - 3433
EP  - 3445
PB  - Springer
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Rosencrantz, Ruben R.
A1  - Vu Hoa Nguyen, 
A1  - Park, Hyunji
A1  - Schulte, Christine
A1  - Böker, Alexander
A1  - Schnakenberg, Uwe
A1  - Elling, Lothar
T1  - Lectin binding studies on a glycopolymer brush flow-through biosensor by localized surface plasmon resonance
JF  - Analytical and bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry and Analusis
N2  - A localized surface plasmon resonance biosensor in a flow-through configuration was applied for investigating kinetics of lectin binding to surface-grafted glycopolymer brushes. Polycarbonate filter membranes with pore sizes of 400 nm were coated with a 114-nm thick gold layer and used as substrate for surface-initiated atom-transfer radical polymerization of a glycomonomer. These grafted from glycopolymer brushes were further modified with two subsequent enzymatic reactions on the surface to yield an immobilized trisaccharide presenting brush. Specific binding of lectins including Clostridium difficile toxin A receptor domain to the glycopolymer brush surface could be investigated in a microfluidic setup with flow-through of the analytes and transmission surface plasmon resonance spectroscopy.
KW  - Localized surface plasmon resonance
KW  - Glycopolymer brush
KW  - Microfluidics
KW  - Bacterial toxin
KW  - Glycosyltransferase
KW  - Biosensors
Y1  - 2016
U6  - https://doi.org/10.1007/s00216-016-9667-9
SN  - 1618-2642
SN  - 1618-2650
VL  - 408
SP  - 5633
EP  - 5640
PB  - Springer
CY  - Heidelberg
ER  -