Split T7 switch-based orthogonal logic operation of fluorogenic RNA aptamer for small molecules detection.

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Advances in fluorescent biosensors are crucial for sensitive molecular detection.
• Existing methods may lack specificity or require complex sample preparation.
• The need for rapid, accurate detection of environmental contaminants is growing.

Purpose of the Study:

• To develop a novel cell-free orthogonal logic gate fluorescent biosensor.
• To enable simultaneous and sensitive detection of atrazine (ATZ) and tetrachlorobiphenyls (PCB77).
• To establish a flexible platform for intelligent multi-input small molecule analysis.

Main Methods:

• Utilized split T7 promoter transcription switches controlled by molecule-probe binding to regulate fluorescent RNA aptamer (Mango) generation.
• Employed a cell-free system leveraging rapid in vitro T7 transcription and a Mango-TO1-Biotin complex for high signal-to-noise ratio.
• Constructed four orthogonal logic gates (AND, NOR, INHIBT, NIMPLY) using ATZ and PCB77 as inputs, controlled by split/intact fluorescent RNA aptamer Mango.

Main Results:

• Achieved highly sensitive detection of ATZ (limit of detection 1.56 pM) and PCB77 (limit of detection 10.2 pM).
• Demonstrated the successful implementation and orthogonality of four distinct logic gates for molecular detection.
• Established a modular platform capable of flexible and sensitive orthogonal operations for small molecule analysis.

Conclusions:

• The developed orthogonal logic gate fluorescent biosensor offers high sensitivity, flexibility, and ease of operation.
• This platform shows significant potential for intelligent multi-input analysis and the detection of various small molecules.
• The cell-free, logic-gate-based approach provides a promising strategy for advanced molecular detection in environmental and biological applications.