Z-Scheme Bismuth-Based Ternary Heterostructured Photoelectrochemical Sensor Integrated with Cu₃P Nanoparticles as a...

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Circulating tumor cells (CTCs) are crucial biomarkers for cancer diagnosis and prognosis.
• Sensitive and accurate detection methods for CTCs are urgently needed for early cancer detection.
• Photoelectrochemical (PEC) sensors offer potential for sensitive biomarker detection.

Purpose of the Study:

• To develop a highly sensitive and precise PEC sensor for detecting MCF-7 cells.
• To utilize a novel dual Z-scheme heterojunction and multifunctional signal probe for enhanced sensing performance.
• To evaluate the sensor's potential for early cancer diagnosis and liquid biopsy.

Main Methods:

• Fabrication of a PEC sensor using dual Z-scheme Bi₂S₃/Bi₂O₂CO₃/Zn_0.5Cd_0.5S heterojunctions and Cu₃P nanoparticles.
• Functionalization with aptamer-magnetic nanobeads (Apt_MUC1-MNs) for selective capture and enrichment of MCF-7 cells.
• PEC signal detection based on photocurrent suppression via p-n semiconductor quenching and enzyme-mimetic catalytic precipitation.

Main Results:

• The PEC sensor achieved an ultrawide linear range from 4 cells/mL to 3 × 10⁵ cells/mL.
• A remarkably low limit of detection (LOD) of 1 cell/mL (S/N = 3) was obtained.
• The sensor demonstrated good selectivity, stability, and reproducibility, with successful validation in human serum samples.

Conclusions:

• The developed PEC sensor provides a novel platform for highly sensitive and precise detection of MCF-7 cells.
• The sensor exhibits significant potential for early cancer diagnosis and liquid biopsy applications.
• This work demonstrates a promising approach for sensitive detection of various biomarkers in clinical settings.