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Gold Albumin Sandwich Structures for Enhanced Biosensing Using Surface Plasmon Resonance
Author(s) -
Rüger Fabian,
Keusgen Michael,
Vornicescu Doru
Publication year - 2021
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.202100029
Subject(s) - surface plasmon resonance , colloidal gold , bovine serum albumin , biosensor , biomolecule , streptavidin , detection limit , materials science , nanotechnology , surface plasmon , nanoparticle , denaturation (fissile materials) , chemistry , plasmon , chromatography , optoelectronics , nuclear chemistry , biotin , biochemistry
The sensitivity of surface plasmon resonance (SPR) is limited by physico‐optical constraints like the quality of the optical elements, resolution of the optical detection element, and temperature control, but also by the surface area of the gold layer, which serves for interaction events. To increase the utilized sensing surface area, gold‐coated chips are loaded with gold nanoparticles (AuNPs). The nanoparticles are synthesized by two different methods and in different sizes. Experimental conditions are elaborated to bind AuNPs stabilized in citrate buffer directly to a SPR surface, which is coated with bovine serum albumin (BSA) prior to binding. The formed sandwich structures are functional without additional coupling steps and provide a time‐efficient tool for rapid and sensitive detection of various biomolecules. The AuNPs are successfully loaded with streptavidin (SaV). This allows convenient immobilization of all kinds of biotinylated molecules (e.g., enzymes, antibodies, etc.). The latter strategy has the advantage to circumvent the denaturation of proteins, which is caused by close contact to gold surfaces. Limit of detection and limit of quantification are found to be in the femtomolar range.