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Updated: Nov 10, 2025
MicroRNA Amplification and Recognition through Locked-nucleic-acid In situ Hybridization as A Novel Detection and Quantification Method
Published on: October 7, 2025
Dual-Mode SERS and Electrochemical Detection of miRNA Based on Popcorn-like Gold Nanofilms and Toehold-Mediated
Hong Zhou1, Jishou Zhang1, Binxiao Li2
1Key Laboratory of Optic-electric Sensing and Analytical Chemistry for Life Science, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
Abstract:
MicroRNA (miRNA) has emerged as one of the ideal target biomarker analytes for cancer detection because its abnormal expression is closely related to the occurrence of many cancers. In this work, we combined three-dimensional (3D) popcorn-like gold nanofilms as novel surface-enhanced Raman scattering (SERS)-electrochemistry active substrates with toehold-mediated strand displacement reactions (TSDRs) to construct a DNA molecular machine for SERS-electrochemistry dual-mode detection of miRNA. 3D popcorn-like spatial structures generated more active "hot spots" and thus enhanced the sensitivity of SERS and electrochemical signals. Besides, the TSDRs showed high sequence-dependence and high specificity. The addition of target miRNA will trigger the molecular machine to perform two TSDRs in the presence of signal DNA strands modified by R6G (R6G-DNA), thus achieving an enzyme-free amplification detection of miRNA with a low limit of detection of 0.12 fM (for the SERS method) and 2.2 fM (for the electrochemical method). This biosensor can also serve as a universally amplified and sensitive detection platform for monitoring different biomarkers, such as cancer-related DNA, messenger RNA, or miRNA molecules, with high selectivity by changing the corresponding probe sequence.
Insights
This study presents a novel DNA molecular machine for sensitive dual-mode detection of microRNA (miRNA) using surface-enhanced Raman scattering (SERS) and electrochemistry. The biosensor achieves ultra-low detection limits for cancer biomarker detection.
Area of Science:
- Biomarker Detection
- Nanomaterials
- Molecular Biology
Background:
- MicroRNA (miRNA) is a crucial biomarker for cancer detection due to its abnormal expression.
- Developing sensitive and specific detection methods for miRNA is essential for early cancer diagnosis.
Purpose of the Study:
- To construct a DNA molecular machine for dual-mode SERS-electrochemistry detection of miRNA.
- To enhance detection sensitivity and specificity using 3D popcorn-like gold nanofilms and toehold-mediated strand displacement reactions (TSDRs).
Main Methods:
- Utilized 3D popcorn-like gold nanofilms as SERS-electrochemistry active substrates.
- Employed TSDRs for enzyme-free amplification and detection of target miRNA.
- Integrated R6G-modified DNA strands for signal generation.
Main Results:
- Achieved a low limit of detection of 0.12 fM for SERS and 2.2 fM for electrochemistry.
- Demonstrated high sequence-dependence and specificity of the TSDRs.
- The 3D nanostructure enhanced SERS and electrochemical signals through increased 'hot spots'.
Conclusions:
- The developed biosensor provides a highly sensitive and specific platform for miRNA detection.
- This dual-mode approach offers a universally amplified detection strategy for various cancer biomarkers by modifying probe sequences.
