One dimensional magneto-optical nanocomplex from silver nanoclusters and magnetite nanorods containing ordered mesocages for sensitive detection of PD-L1

Publication year: 2021
Authors: Xing Huang a,1 Zhao-huan Zhang b,1 Jie Chen a,c, Zhihui Mao a,d, Han Zhu a, Yawen Liu c,d,Zhongzheng Zhu e, Hongxia Chen a

a - Center for Molecular Recognition and Biosensing, School of Life Sciences, Shanghai University, Shanghai, 200444, PR China
b - Department of Laboratory Medicine, Changzheng Hospital, Naval Medical University, Shanghai, 200003, PR China
c - School of Medicine, Shanghai University, Shanghai, 200444, PR China
d - School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China
e - Department of Oncology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, 301 Middle Yanchang Road, Shanghai, 200072, PR China

Published in: Biosensors and Bioelectronics, 2021, Vol. 189, p. 113385
doi: 10.1016/j.bios.2021.113385

Programmed death ligand 1 (PD-L1) is a typical immune checkpoint protein, whose up-regulation on the membrane of different tumor cells inhibits the immune response of T cells and leads to the escape of tumor cells. In this work, we designed a facile and highly specific surface plasmon resonance (SPR) biosensor to detect PD-L1 in human plasma based on magnetite nanorods containing ordered mesocages (MNOM) and silver nanoclusters (AgNCs). Magneto-optical nanocomplex MNOM@AgNCs with superior magneto-optical properties and high signal-to-noise ratio were fabricated to improve the detection sensitivity owing to the high specific surface area of MNOM and excellent localized SPR of AgNCs. The PD-L1 Antibody on the surface of gold chip and the PD-L1 aptamer on MNOM@AgNCs could realize dual selective recognition of PD-L1, providing the specificity of the sensor and reducing non-specific binding. The SPR sensor showed a good linear range of PD-L1 from 10 ng/mL to 300 ng/mL with the detection limit of 3.29 ng/mL. The practical performance of this immunosensing platform had been successfully verified by clinical samples which included healthy donors and cancer patients. Based on the analysis, the developed immunosensor provided a new strategy for point-of-care detection of PD-L1 and could be used as clinical companion diagnosis of PD-1/PD-L1 inhibitor therapy.

MP-SPR keywords: magnetite nanorods, signal amplification, silver nanoclusters