A regenerative label-free fiber optic sensor using surface plasmon resonance for clinical diagnosis of fibrinogen.
OBJECTIVE
We present the regenerative label-free fiber optical biosensor that exploits surface plasmon resonance for quantitative detection of fibrinogen (Fbg) extracted from human blood plasma.


METHODS
The sensor head was made up of a multimode optical fiber with its polymer cladding replaced by metal composite of nanometer thickness made of silver, aluminum, and nickel. The Ni layer coated allowed a direct immobilization of histidine-tagged peptide (HP) on its metal surface without an additional cross-linker in between. On the coated HP layer, immunoglobulin G was then immobilized for specific capturing of Fbg.


RESULTS
We demonstrated a real-time quantitative detection of Fbg concentrations with limit of detection of ~10 ng/mL. The fact that the HP layer could be removed by imidazole with acid also permitted us to demonstrate the regeneration of the outermost metal surface of the sensor head for the sensor reusability.


CONCLUSIONS
The sensor detection limit was estimated to be ~10 pM, which was believed to be sensitive enough for detecting Fbg during the clinical diagnosis of cardiovascular diseases, myocardial infarction, strokes, and Alzheimer's diseases.
Department of Bionano Technology, College of Bionano Technology, Gachon University, Seongnam, South Korea.
Tan Tai
TT
Nguyen
Department of Bionano Technology, College of Bionano Technology, Gachon University, Seongnam, South Korea.
Sun Oh
SO
Bea
Department of Materials Science and Engineering, Hongik University, Sejong City, South Korea.
Dong Min
DM
Kim
Department of Chemical and Bio Engineering, Gachon University, Seongnam, South Korea.
Won Jung
WJ
Yoon
Department of Chemical and Biomolecular Engineering, College of Energy and Biotechnology, Seoul National University of Science and Technology, Seoul, South Korea.
Jin-Won
JW
Park
Department of Bionano Technology, College of Bionano Technology, Gachon University, Seongnam, South Korea.
Seong Soo A
SS
An
Department of Bionano Technology, College of Bionano Technology, Gachon University, Seongnam, South Korea ; Department of Nanophysics, College of Bionano Technology, Gachon University, Seongnam, South Korea ; Neuroscience Institute, Gil Hospital, Incheon, South Korea.
Heongkyu
H
Ju
D005340:Fibrinogen / Q000032:analysis*; D006801:Humans; D057230:Limit of Detection; D055100:Optical Fibers; D020349:Surface Plasmon Resonance / Q000295:instrumentation* / Q000379:methods*
D005340:Fibrinogen
SPR; histidine-tagged peptide; protein sensing; real-time assay