A sensitive biosensor with a DNAzyme for lead(II) detection based on fluorescence turn-on

Area of Science:

• Analytical Chemistry
• Biochemistry
• Environmental Science

Background:

• Lead (Pb2+) is a toxic heavy metal pollutant with significant environmental and health concerns.
• Accurate and sensitive detection methods for Pb2+ are crucial for environmental monitoring and public health.
• DNAzyme-based biosensors offer a promising platform for developing selective and sensitive detection tools.

Purpose of the Study:

• To develop and characterize a new DNAzyme-based fluorescent biosensor for the detection of Pb2+.
• To evaluate the sensor's sensitivity, selectivity, and applicability in real-world samples.

Main Methods:

• Design of a DNAzyme-substrate system incorporating fluorescein amidite (FAM) and ethidium bromide (EB).
• Utilizing Förster Resonance Energy Transfer (FRET) between FAM and EB, modulated by Pb2+-induced DNAzyme activity.
• Measurement of fluorescence enhancement of FAM as an indicator of Pb2+ concentration.

Main Results:

• The biosensor demonstrated a linear response for Pb2+ detection in the range of 0-100 nM.
• A low detection limit of 530 pM for Pb2+ was achieved under optimal conditions.
• The sensor exhibited high selectivity against common interference ions and provided satisfactory results in river water samples.

Conclusions:

• The developed DNAzyme fluorescent biosensor is highly sensitive, selective, and simple for Pb2+ detection.
• This method offers a robust platform for environmental monitoring of lead contamination.
• The sensor design provides a versatile foundation for developing other DNAzyme-based biosensing applications.