An aptamer-based fluorescent biosensor for potassium ion detection using a pyrene-labeled molecular beacon

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Molecular Biology

Background:

• Potassium ion (K+) is crucial for physiological functions.
• Accurate K+ monitoring is vital for diagnosing and managing various health conditions.
• Existing K+ detection methods may lack sensitivity or specificity for biological samples.

Purpose of the Study:

• To develop a novel and sensitive biosensor for the determination of potassium ions (K+).
• To utilize aptamers as molecular recognition elements and pyrene-labeled fluorescent probes for signal transduction.
• To achieve high selectivity and sensitivity for K+ detection in biological environments.

Main Methods:

• A biosensor was designed using an aptamer for K+ recognition.
• Pyrene moieties labeled on a complementary oligonucleotide acted as fluorescent probes.
• The displacement of the complementary oligonucleotide upon K+ binding induced a change in pyrene fluorescence (excimer vs. monomer emission).

Main Results:

• The biosensor demonstrated a linear response of fluorescence intensity to K+ concentration from 6.0 x 10(-4) to 2.0 x 10(-2) M.
• A low detection limit of 4.0 x 10(-4) M for K+ was achieved.
• The method exhibited high selectivity for K+ in the presence of other biologically relevant ions (Na+, NH4+, Mg2+, Ca2+).

Conclusions:

• The developed aptamer-based fluorescent biosensor is a sensitive and selective tool for K+ determination.
• The assay's simplicity and specificity make it suitable for potential applications in biological and clinical settings.
• This novel approach offers a promising alternative for real-time K+ monitoring.