A plasmonic MNAzyme signal amplification strategy for quantification of miRNA-4739 breast cancer biomarker

• Published in: Analytica chimica acta 2024-01, Vol.1285, p.341999-341999, Article 341999
• Main Authors: Larraga-Urdaz, Andrea L., Moreira-Álvarez, Borja, Encinar, Jorge Ruiz, Costa-Fernández, José M., Fernández-Sánchez, María Luisa
• Format: Article
• Language: English
• Subjects: Biomarker; Biomarkers, Tumor; Biosensing Techniques - methods; Breast Neoplasms - diagnosis; Female; Gold - chemistry; Gold nanoparticles; Humans; Limit of Detection; Metal Nanoparticles - chemistry; MicroRNAs - analysis; miRNA; Multicomponent nucleic acid enzymes; Nucleic Acid Amplification Techniques - methods; Nucleic Acids; Signal-amplification
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2023.341999

A major challenge in the 21st century is the development of point-of-care diagnostic tools capable to detect and quantify disease biomarkers in a straightforward, affordable, sensitive, and specific manner. The remarkable plasmonic properties of gold nanoparticles (AuNPs) have promoted their use for development of simple methodologies for nucleic acid detection in combination with a variety of oligonucleotides amplification techniques. Here, assemblies of AuNPs with Multicomponent Nucleic Acid enzymes (MNAzymes) has been successfully used in the design of a highly sensitive and simple bioassay for rapid spectroscopic detection and quantification of miRNA-4739 in blood samples. The miRNA selected is a doxorubicin chemoresistant biomarker in breast cancer which overexpression promotes the proliferation, progression, and survival of cancer cells. In this work, two alternatives experimental designs, based on use of MNAzymes and AuNPs, have been optimized and applied for sensitive miRNA-4739 quantification: one based on a traditional direct measurement of wavelength shift and a second non-conventional simple approach based on isolation and measurement of free nanoparticles absorbance. Improvement in sensitivity and, higher measurement accuracy and precision were achieved with the second approach. The developed bioassay provides a detection limit as low as 7 pmolL−1 for miRNA-4739 quantification and performed satisfactory selectivity and well practical applicability by analysis of the miRNA-4739 in blood, demonstrating that the proposed strategy is a promising and suitable spectroscopic method for breast cancer diagnosis thought liquid biopsy of circulating tumoral cells. [Display omitted] •Two spectroscopic methodologies were critically evaluated for miRNA quantification.•A MNAzyme isothermal signal amplification allowed a high detection sensitivity.•Direct colorimetric detection is advisable for screening/qualitative analysis.