# Development of a Modular miRNA-Responsive Biosensor for Organ-Specific Evaluation of Liver Injury

## TL;DR

This paper introduces a new biosensor that detects microRNAs in a specific organ, offering a promising tool for diagnosing diseases like liver injury.

## Contribution

The study introduces a modular miRNA-responsive biosensor with organ-specific targeting for disease diagnostics.

## Key findings

- The miR-RBS biosensor effectively detected miR-122 levels in a drug-induced liver injury model.
- The modular design allows customization for organ-specific miRNA detection and cell targeting.
- The biosensor provides rapid and accurate disease reporting through fluorescence signaling.

## Abstract

MicroRNAs (miRNAs) are increasingly being considered essential diagnostic biomarkers and therapeutic targets for multiple diseases. In recent years, researchers have emphasized the need to develop probes that can harness extracellular miRNAs as input signals for disease diagnostics. In this study, we introduce a novel miRNA-responsive biosensor (miR-RBS) designed to achieve highly sensitive and specific detection of miRNAs, with a particular focus on targeted organ-specific visualization. The miR-RBS employs a Y-structured triple-stranded DNA probe (Y-TSDP) that exhibits a fluorescence-quenched state under normal physiological conditions. The probe switches to an activated state with fluorescence signals in the presence of high miRNA concentrations, enabling rapid and accurate disease reporting. Moreover, the miR-RBS probe had a modular design, with a fluorescence-labeled strand equipped with a functional module that facilitates specific binding to organs that express high levels of the target receptors. This allowed the customization of miRNA detection and cell targeting using aptameric anchors. In a drug-induced liver injury model, the results demonstrate that the miR-RBS probe effectively visualized miR-122 levels, suggesting it has good potential for disease diagnosis and organ-specific imaging. Together, this innovative biosensor provides a versatile tool for the early detection and monitoring of diseases through miRNA-based biomarkers.