Highly Sensitive Electrochemical Biosensors for miRNA-122 Detection with Two-Dimensional MoS ₂ Monolayers

Accurate and ultrasensitive detection of miRNA-122 plays an important role in early diagnosis of several liver-related diseases, particularly hepatocellular carcinoma and hepatitis C. A highly sensitive electrochemical biosensor integrating MoS 2 monolayer with AuNPs is presented with a view to selective detections of natural and mutant miRNA-122. The synergy between MoS 2 monolayers and AuNPs promotes oligonucleotide immobilization and signal transduction, contributing to the improved detection sensitivity for miRNA-122. The biosensor enables label-free detection over a broad dynamic range (10 –7 to 10 nM) with a low limit of detection (LOD) of 4.27 × 10 –9 nM. This platform demonstrates high sensitivity, specificity, and reproducibility, outperforming conventional DNA-based probes in miRNA recognition. Additionally, this MoS 2 -based biosensor has the potential to be cost-effective with rapid detection capability, which is advantageous for precision diagnostics and early monitoring of hepatitis-related diseases.