DNAzyme nanomotor-based logic biocomputing system for highly reliable intracellular microRNAs imaging and cancer cell...

The intricate progression of diseases is associated with alterations in relevant microRNAs (miRNAs). However, intracellular miRNA expression is often overlapping and nonspecific, and analysis of a single miRNA target may not offer comprehensive insights into disease states. Current DNA nanomotor technology focus on single target detection, restricting their diagnostic performance. Therefore, multiple intracellular miRNAs analysis is essential for accurate cell type discrimination and diseases diagnosis.

A DNAzyme nanomotor-based logic biocomputing system was developed for reliable intracellular miRNA imaging and cancer cell discrimination. The nanomotor comprises substrate strands and a flexible DNAzyme-Lock duplex assembled on gold nanoparticles (AuNPs). MiR-155 and miR-10b were selected as model targets due to their specific relevance to cancer. In the absence of targets, the nanomotor remains in an "OFF" state. Upon target binding, the DNAzyme strand is released and spontaneously switches to an "ON" state, achieving signal amplification with a detection limit of 35.3 pM. By rationally designing the target-responsive DNAzyme and Lock strands, a molecular biocomputing system incorporating YES, AND, and OR logic gates was constructed to generate defined fluorescence outputs in response to specific combinations of miRNA inputs. Integration of these outputs enables accurate discrimination between different cell lines in complex intracellular biomolecular networks.

This strategy integrates multiple miRNA signals through molecular logic computation, overcoming the limited specificity of single-biomarker analysis. This resulting platform enables precise cell types discrimination and provides a versatile framework for intracellular biomolecular computation and cancer cell recognition.