Cell Membrane and V<sub>2</sub>C MXene-Based Electrochemical Immunosensor with Enhanced Antifouling Capability for Detection of CD44
Meiling Lian, Yuqing Shi, Liuxing Chen, Yongji Qin, Wei Zhang, Jingbo Zhao, Da Chen
Abstract
The inactive adsorption and interference of biomolecules in electrochemical biosensors is a topic of intense interest. Directly utilizing native cell membranes to endow electrochemical surfaces with antifouling and biocompatible features is a promising strategy, rather than attempting to synthetically replicate complex biological interface properties. In this study, we present a facial and sensitive sandwich-type antifouling immunoassay through platelet membrane/Au nanoparticle/delaminated V 2 C nanosheet (PM/AuNPs/d-V 2 C)-modified electrode as the substrate of sensing interface and methylene blue/aminated metal organic framework (MB@NH 2 -Fe-MOF-Zn) as an electrochemical signal probe. The biosensor perfectly integrates the high conductivity of AuNPs-loaded V 2 C MXene with the excellent loading property of NH 2 -Fe-MOF-Zn to improve the electrochemical sensing performance. In addition, the excellent antifouling properties of the homogeneous cell membrane can effectively prevent the non-specific adsorption of model proteins. The obtained antifouling biosensor possesses the capability of ultrasensitive detection of CD44 and CD44-positive cancer cell in complex liquids and exhibits good analytical performance for the analysis of CD44 with a linear range from 0.5 ng/mL to 500 ng/mL. This strategy of developing cell membrane-based biosensing systems with enhanced antifouling capability can be easily expanded to the construction of other complex biosensors, and the advanced biological probes and analytical methods provide a favorable means to accurately quantify biomarkers associated with tumor progression.