Label-free and specific detection of soluble programmed death ligand-1 using a localized surface plasmon resonance biosensor based on excessively tilted fiber gratings

Binbin Luo; Yajie Wang; Huafeng Lu; Shengxi Wu; Youming Lu; Shenghui Shi; Lingchen Li; Shanghai Jiang; Mingfu Zhao

doi:10.1364/BOE.10.005136

Label-free and specific detection of soluble programmed death ligand-1 using a localized surface plasmon resonance biosensor based on excessively tilted fiber gratings

Biomed Opt Express. 2019 Sep 13;10(10):5136-5148. doi: 10.1364/BOE.10.005136. eCollection 2019 Oct 1.

Authors

Binbin Luo^{1

2}, Yajie Wang¹, Huafeng Lu¹, Shengxi Wu^{3

4}, Youming Lu³, Shenghui Shi¹, Lingchen Li³, Shanghai Jiang¹, Mingfu Zhao¹

Affiliations

¹ Chongqing Key Laboratory of Optical Fiber Sensor and Photoelectric Detection, Chongqing University of Technology, Chongqing 400054, China.
² luobinbin@cqut.edu.cn.
³ School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China.
⁴ sxwu2004@cqut.edu.cn.

Abstract

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.