AgI Precipitation Induced Polarity Reversal with Formation of Z-Type Heterojunction for Photoelectrochemical Sensing.
Anal Chem
; 96(37): 14759-14765, 2024 Sep 17.
Article
in En
| MEDLINE
| ID: mdl-39234645
ABSTRACT
Regulating photocurrent polarity is highly attractive for fabricating photoelectrochemical (PEC) biosensors with improved sensitivity and accuracy in practical samples. Here, a new approach that adopts the in situ generated AgI precipitate and AgNCs to reversal Bi2WO6 polarity with formation of Z-type heterojunction was proposed for the first time, which coupled with a high-efficient target conversion strategy of exonuclease III (Exo III)-assisted triple recycling amplification for sensing miRNA-21. The target-related DNA nanospheres in situ generated on electrode with loading of plentiful AgI and AgNCs not only endowed the photocurrent of Bi2WO6 switching from the anodic to cathodic one due to the changes in the electron transfer pathway but also formed AgI/AgNCs/Au/Bi2WO6 Z-type heterojunction to improve the photoelectric conversion efficiency for acquiring extremely enhanced PEC signal, thereby significantly avoiding the problem of high background signal derived from traditional unidirectional increasing/decreasing response and false-positive/false-negative. Experimental data showed that the PEC biosensor had a low detection limit down to 0.085 fM, providing a new polarity-reversal mechanism and expected application in diverse fields, including biomedical research and clinical diagnosis.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Biosensing Techniques
/
Silver Compounds
/
MicroRNAs
/
Electrochemical Techniques
Limits:
Humans
Language:
En
Journal:
Anal Chem
Year:
2024
Document type:
Article
Country of publication: