RNA Mango-based sensors for lead.

Area of Science:

• Biochemistry
• Molecular Biology
• Environmental Science

Background:

• Lead (Pb²⁺) toxicity is a significant global health concern, necessitating rapid and accessible detection methods.
• Existing lead detection tools often lack the desired sensitivity, cost-effectiveness, or ease of use.
• RNA aptamers offer potential as molecular recognition elements for biosensor development.

Purpose of the Study:

• To develop and validate a sensitive and selective fluorescence-based sensor for lead (Pb²⁺) detection using the RNA Mango aptamer.
• To investigate the mechanism of Pb²⁺-induced fluorescence activation in the RNA Mango system.
• To assess the sensor's performance, including its limit of detection and selectivity, for practical applications.

Main Methods:

• Utilizing the RNA Mango aptamer as a recognition element for Pb²⁺.
• Investigating Pb²⁺-induced G-quadruplex formation and subsequent dye binding (TO1-biotin, TO3-biotin, thioflavin-T).
• Characterizing fluorescence properties and determining binding affinities (K_D) and limits of detection (LOD).

Main Results:

• RNA Mango, in conjunction with TO1-biotin, demonstrated high binding affinity for Pb²⁺ (K_D ~ 40 nM).
• The sensor achieved sub-micromolar affinity for Pb²⁺ with all tested dyes.
• Detected low nanomolar concentrations of Pb²⁺ (LOD 2-16 nM), below permissible drinking water limits.
• Exhibited remarkable selectivity for Pb²⁺ and successfully detected it in tap water samples.

Conclusions:

• The RNA Mango aptamer serves as a sensitive and selective platform for developing simple, inexpensive fluorescence-based lead sensors.
• This RNA-based sensor offers a promising alternative for rapid and cost-effective monitoring of lead contamination.
• The findings expand the utility of RNA aptamers in environmental monitoring and diagnostics.