Open AccessLabel-free and specific detection of soluble programmed death ligand-1 using a localized surface plasmon resonance biosensor based on excessively tilted fiber gratings
Author(s) -
Binbin Luo,
Yajie Wang,
Haitao Lu,
Shanshan Wu,
Yunxiang Lu,
Shanshan Shi,
Lingchen Li,
Shanghai Jiang,
Mingfu Zhao
Publication year - 2019
Publication title -
biomedical optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.362
H-Index - 86
ISSN - 2156-7085
DOI - 10.1364/boe.10.005136
Subject(s) - surface plasmon resonance , biosensor , detection limit , materials science , ligand (biochemistry) , monoclonal antibody , nanoshell , surface plasmon , nanotechnology , plasmon , chemistry , nanoparticle , antibody , optoelectronics , receptor , chromatography , medicine , immunology , biochemistry
Programmed death ligand-1 (PD-L1) plays an important role in tumor evasion from the host immune system. The level of soluble PD-L1 (sPD-L1) in serum is closely related to tumor aggressiveness and outcomes. This study aimed to propose a localized surface Plasmon resonance (LSPR) biosensor based on excessively tilted fiber grating (ExTFG) coated with large-sized (∼160 nm) gold nanoshells for label-free and specific detection of sPD-L1. The experimental results showed that the limit of detection (LOD) of the immunosensor for sPD-L1 in buffer solutions was ∼1 pg/mL due to the enhanced LSPR effect resulting from the interaction between sPD-L1 molecules and anti-sPD-L1 monoclonal antibodies. The detection of sPD-L1 in complex serum media, such as fetal bovine serum, confirmed that the label-free immunosensor was extremely specific to sPD-L1 and could identify it at a concentration as low as 5 pg/mL. Therefore, it can be potentially applied in clinic for the fast and early diagnosis of cancer.