Ti3C2Tx MXene -facilitated non-selective trapping effect: Efficient SERS detection of exosomal PD-L1

Yangyang Zhou; Qiang Chen; Suyun Zhong; Hezhen Liu; Kwangnak Koh; Hongxia Chen

doi:10.1016/j.bios.2023.115493

Ti₃C₂Tx MXene -facilitated non-selective trapping effect: Efficient SERS detection of exosomal PD-L1

Biosens Bioelectron. 2023 Oct 1:237:115493. doi: 10.1016/j.bios.2023.115493. Epub 2023 Jun 21.

Authors

Yangyang Zhou¹, Qiang Chen², Suyun Zhong³, Hezhen Liu³, Kwangnak Koh⁴, Hongxia Chen⁵

Affiliations

¹ School of Medicine, Shanghai University, Shanghai, 200444, PR China; School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, PR China.
² School of Medicine, Shanghai University, Shanghai, 200444, PR China.
³ School of Life Sciences, Shanghai University, Shanghai, 200444, PR China.
⁴ Institute of General Education, Pusan National University, Busan, 609-735, Republic of Korea.
⁵ School of Life Sciences, Shanghai University, Shanghai, 200444, PR China. Electronic address: hxchen@shu.edu.cn.

PMID: 37364303
DOI: 10.1016/j.bios.2023.115493

Abstract

Biosensors developed through a sandwich approach have demonstrated favorable detection performance for exosomal programmed cell death 1 ligand 1 (ExoPD-L1) detection. However, the reported PD-L1 antibodies, peptides, and aptamers utilized in these biosensors typically bind to the extracellular region, with overlapping binding sites that severely constrain the fabrication of biosensors. In this study, we present a simple approach to specifically identify and analyze ExoPD-L1 through the non-selective trapping effect of Ti₃C₂T_X (X=-O, -F, -OH) MXene on exosomes via the formation of Ti-O-P complexation, and the selective capture of peptide-functionalized Au@MPBA (4-Mercaptophenylboronic acid) @SiO₂ surface enhanced Raman scattering (SERS) tags on ExoPD-L1. The biosensor delivered a both hypersensitive and reliable performance in exosome detection with a low limit of detection (20.74 particles/mL) in the linear range of 10² to 5×10⁶ particles/mL. Furthermore, the biosensor demonstrated excellent stability and interference resistance in detecting ExoPD-L1 in clinical serum samples, enabling the easy differentiation of breast cancer patients from healthy controls. This work provides new insights into the design of biosensors for exosome detection and can serve as a replicable template for sandwich immunoassay detection for other types of sensors, including but not limited to SERS.

Keywords: Au@MPBA@SiO(2); Detection; Exosomal PD-L1; SERS nanotag; Serum.