Organic Photoelectrochemical Transistor/Visual Sensing Platform Based on CS/MCS Schottky Heterojunction and...

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Developing sensitive nucleic acid detection methods is crucial for early disease diagnosis.
• Existing technologies face limitations in sensitivity and on-site applicability.
• MicroRNA-21 (miRNA-21) is a key biomarker for various cancers.

Purpose of the Study:

• To develop a dual-mode sensing platform for ultrasensitive detection of miRNA-21.
• To integrate organic electrochemical transistors (OPECT) and colorimetry for enhanced detection.
• To establish a novel biosensing platform for early cancer diagnosis.

Main Methods:

• Synthesized a 1D/3D Co9S8/Mn0.3Cd0.7S Schottky heterojunction as a photoactive material.
• Integrated a quadruple signal amplification mechanism involving catalytic hairpin assembly (CHA), CRISPR/Cas12a, tandem strand displacement reaction (TSDR), and hybrid chain reaction (HCR).
• Utilized G-quadruplex/hemin DNAzyme (GQH DNAzyme) for dual-signal output via OPECT and TMB colorimetric reactions.

Main Results:

• Achieved ultrasensitive detection of miRNA-21 with a limit of detection as low as 36.5 aM (OPECT) and 3.8 fM (colorimetry).
• Demonstrated enhanced photoelectric conversion efficiency using the synthesized heterojunction material.
• Successfully integrated biological, chemical, and electronic signal amplification for synergistic enhancement.

Conclusions:

• The developed dual-mode biosensing platform offers a new solution for accurate miRNA analysis in early cancer diagnosis.
• The synergistic triple-modal amplification strategy significantly improves detection sensitivity.
• This platform holds promise for point-of-care diagnostics and personalized medicine.