Aptamer and Thiol Co-Regulated Color-Shifting Fluorophores via Dynamic Through-Bond/Space Conjugation for...

Area of Science:

• Biochemistry
• Molecular Biology
• Analytical Chemistry

Background:

• Color-shifting fluorophores are crucial for quantitative RNA sensing.
• Triphenylmethane dyes offer potential for novel sensor development.

Purpose of the Study:

• To report the synthesis and properties of de-conjugated triphenylmethane leucomalachite green (LMG).
• To demonstrate the application of LMG in a programmable RNA sensor for quantitative analysis.
• To achieve accurate and rapid quantification of Aflatoxin 1.

Main Methods:

• Rapid synthesis of LMG from malachite green (MG) in a reductive transcription system.
• Utilizing co-transcribed MG RNA aptamer (MGA) for fluorescence switching.
• Employing a 3-way junction (3WJ)-based rolling circle transcription switch for steric allosterism.

Main Results:

• LMG exhibits UV fluorescence via space conjugation and red fluorescence upon MGA binding via through-bond conjugation.
• The developed RNA sensor system achieved picomolar-level quantification of Aflatoxin 1 in one hour.
• The system demonstrated high accuracy and programmability, applicable to various targets.

Conclusions:

• LMG is a novel, easily synthesized color-shifting fluorophore with potential in RNA sensing.
• The developed 3WJ-based transcription switch system offers a standardized and universally applicable method for quantitative aptamer-based sensing.
• This approach enables rapid and accurate detection of analytes like Aflatoxin 1.