Surface Engineering of MXene and Functional Fullerenols for Cancer Biomarker 'eIF₃d'

Selective and sensitive detection of eIF₃d (eukaryotic translation initiation factor 3 complex, subunit D), a protein biomarker, is of fundamental significance for the diagnosis of various cancers. Here, we report an electrochemical sensor based on MXene and aspartic acid-functionalized fullerenol (F-Asp) for the biosensing of eIF₃d. To construct such an innovative sensing platform, MXene was first synthesized, followed by the convenient functionalization of fullerenol with aspartic acid groups (F-Asp) through hydroxylation and activation of fullerenes. Finally, a bioplatform was created for eIF₃d sensing by modifying the graphite electrode (GE) surface with MXene and F-Asp, followed by surface functionalization with anti-eIF₃d antibody via EDC/NHS chemistry. Detailed electrochemical and analytical material characterization methods were utilized after each surface modification step. Notably, the surface-engineered MXene:F-Asp showed superior electrochemical features. The sensor's response to eIF₃d was achieved in the linear range of 10 to 250 ng/mL, with a detection limit of 0.14 ng/mL. The selectivity of the sensor was assessed by monitoring its response to eIF₃d in the presence of a variety of interfering compounds. Analysis of eIF₃d was effectively performed in synthetic serum samples. The promising electrochemical sensing properties of the designed sensor suggest great potential for various real-time health monitoring applications.