Temperature-Robust DNAzyme Biosensors Confirming Ultralow Background Detection.

Area of Science:

• Biotechnology and Biosensing
• Analytical Chemistry
• Molecular Biology

Background:

• DNAzymes are widely used in biosensors for metal ion analysis.
• Traditional DNAzyme biosensors face challenges with high and fluctuating background signals.
• There is a need for robust and sensitive DNAzyme biosensors with improved detection limits.

Purpose of the Study:

• To develop a temperature-robust DNAzyme biosensor with ultralow background.
• To enhance the sensitivity and reliability of metal ion detection using DNAzymes.
• To create a facile and effective design for practical applications in environmental and food safety monitoring.

Main Methods:

• A novel temperature-robust DNAzyme was designed and synthesized.
• A sequential detection process utilizing proximity fluorescent probes was employed.
• The biosensor's performance was evaluated across various temperatures and for selectivity against interfering ions.

Main Results:

• The developed DNAzyme biosensor demonstrated an ultralow background across a temperature range of 20–41 °C.
• A signal-to-background ratio exceeding 20 was achieved.
• A detection limit of 0.22 nM for Pb²⁺ was obtained, with over 6000-fold selectivity against Zn²⁺.
• Successful application in detecting lead pollution in tap water and eggs with high recovery rates (87–114%).

Conclusions:

• The proposed temperature-robust DNAzyme biosensor significantly reduces background noise, enhancing sensitivity and reliability.
• This design strategy offers a robust platform for metal ion detection, applicable to real-world samples.
• The facile and effective approach facilitates practical applications in environmental monitoring and food safety analysis.