An immunosensor integrating SERS and upconversion luminescence for dual-mode detection of CA125 in ovarian carcinoma

Dual-mode detection integrating SERS and UCL for sensitive and visualized detection of CA125. • A type-II band alignment for efficient charge transfer was featured via MXene/MoS 2 heterostructure. • The dual-mode immunoassay kit was developed as a practical tool for clinical ovarian cancer diagnostics. Ovarian cancer (OC) is one of the most common cancers with a high mortality rate, posing a severe threat to female health. Cancer antigen 125 (CA125) has been broadly acknowledged as a significant oncomarker for monitoring OC. Herein, we present a dual-mode immunosensor that integrates surface-enhanced Raman scattering (SERS) and upconversion luminescence (UCL) to facilitate the sensitive and visualized detection of CA125. The MXene/MoS 2 composites were employed as the SERS substrate, whose abundant surface functional groups enable robust antibody immobilization while efficient interfacial charge transfer markedly boost the chemical enhancement. Specifically, a typical type-II band alignment was observed in MXene/MoS 2 heterostructure, which was favorable for efficient charge transfer and resulted in a significant SERS effect with an enhancement factor of 5.24 × 10 7 . Furthermore, the co-doped Yb 3+ /Er 3+ ions UCL probes were employed to improve the detection capability for CA125 by visible green fluorescence. The developed dual-mode immunosensor demonstrated a wide linear detection response, covering the range from 10 to 10 −4  IU/mL. Moreover, the immunosensor displayed a highly sensitivity in detecting of CA125, with a limit of detection as 4.46 × 10 −5  IU/mL for SERS mode and 5.01 × 10 −5  IU/mL for UCL mode. Based on the favorable dual-mode immunosensor, it is proposed as a reliable tool that shows great potential for the detection of CA125. Download: Download high-res image (334KB) Download: Download full-size image