Spatial-Resolved Photoelectrochemical Biosensing Array Based on a CdS@g-C₃N₄ Heterojunction: A Universal...

Area of Science:

• * Materials Science and Nanotechnology
• * Analytical Chemistry
• * Biomedical Engineering

Background:

• * Accurate and sensitive detection of biomarkers in real biosamples is a significant challenge.
• * Prostate-specific antigen (PSA) is a key biomarker for prostate cancer diagnosis.
• * Existing detection methods often lack sensitivity, accuracy, or applicability in complex biological matrices.

Purpose of the Study:

• * To develop a universal spatial-resolved photoelectrochemical (PEC) ratiometry for sensitive and accurate biodetection of PSA.
• * To utilize a novel CdS@g-C3N4 heterojunction and CuS quantum dots (QDs) for signal amplification and enhanced PEC performance.
• * To establish a ratiometric detection strategy for improved reliability and specificity in real biosamples.

Main Methods:

• * Synthesis and immobilization of CdS@g-C3N4 p-n heterojunction on a dual-electrode array.
• * Modification of electrodes with gold nanoparticles and PSA antibodies, coupled with PSA-labeled CuS QDs.
• * Spatial-resolved PEC measurements using a dual-electrode system with one working electrode and one reference electrode for ratiometric analysis.

Main Results:

• * The developed ratiometric PEC system demonstrated high sensitivity for PSA detection.
• * A linear detection range from 1.0 × 10^-11 to 5.0 × 10^-8 g mL^-1 was achieved.
• * A limit of detection as low as 4.0 pg mL^-1 was obtained, indicating superior analytical performance.

Conclusions:

• * The novel spatial-resolved PEC ratiometry provides a highly sensitive and accurate platform for biomarker detection.
• * The combination of CdS@g-C3N4 heterojunction and CuS QDs offers effective signal amplification and enhanced PEC properties.
• * This approach shows promise for practical applications in real biosamples, offering a new paradigm for sensitive biodetection.