Hot-Hole Injection-Enabled Efficient Signal Modulation for Boosting Sensitive Paper-Based Photocathodic Analysis...

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Cathodic photoelectrochemical (PEC) assays offer advantages in anti-interference and photocorrosion resistance for real sample analysis.
• However, limited cathodic PEC response leads to suboptimal detection performance.

Purpose of the Study:

• To develop a novel hot-hole injection effect (HIE)-enabled strategy for modulating PEC signals.
• To create a highly sensitive photocathodic sensing platform for microRNA detection.

Main Methods:

• Fabrication of atom-shared plasmonic Bi-Bi2O3 (AS-BBO) hetero-nanostructures with oxygen vacancies.
• Utilizing CoFe2O4 as a hole sink to control HIE efficacy for signal modulation.
• Development of a paper-based photocathodic sensing platform for microRNA-221 detection.

Main Results:

• The AS-BBO nanostructure demonstrated an enhanced cathodic PEC signal due to efficient hot-hole injection and prolonged carrier lifetime.
• Target-induced modulation of HIE by CoFe2O4 resulted in a sharp photocurrent quenching.
• Achieved a low detection limit of 80 aM and a wide linear range (0.25 fM to 2 nM) for microRNA-221 detection.

Conclusions:

• The HIE strategy provides an effective means to enhance cathodic PEC response and improve detection sensitivity.
• The developed AS-BBO based sensor demonstrates high performance for microRNA detection in complex samples.
• This work establishes a foundation for utilizing HIE in advanced photocathodic analysis.