Concentration-Adaptive AND-Gate Probe Enables High-Fidelity Imaging of miRNA in Live Cells

Area of Science:

• Biomedical Engineering
• Molecular Diagnostics
• Cancer Research

Background:

• Tumor microenvironment exhibits abnormal signals like elevated ATP.
• Current probes often target single analytes, leading to background noise.
• Catalytic hairpin assembly (CHA) offers enzyme-free amplification but needs improvement.

Purpose of the Study:

• To design a novel nucleic acid probe for simultaneous detection of ATP and miR-21.
• To develop a highly specific and sensitive diagnostic tool for early tumor detection.
• To overcome limitations of single-target probes and background signal leakage.

Main Methods:

• Designed ATMiR-LOCK, a hybrid probe integrating a dual-ATP aptamer with two CHA hairpins.
• Utilized an "AND" logic gate mechanism requiring both ATP and miR-21 for signal output.
• Validated the probe using in vitro experiments, fluorescence imaging in cancer cells, and multi-cell line testing.

Main Results:

• ATMiR-LOCK demonstrated synchronous response to ATP and miR-21.
• Achieved high sensitivity with a picomolar detection limit for miR-21.
• Showcased excellent specificity and reliability in detecting cellular ATP and miR-21 in cancer cells.

Conclusions:

• The ATMiR-LOCK probe offers a dual-input strategy for enhanced detection specificity.
• This system effectively minimizes background signals, improving diagnostic accuracy.
• Represents a promising tool for developing highly specific diagnostic strategies for early tumor detection.