Lipopolysaccharide-Specific Aptasensor: A Spectroscopic Approach for Identifying Gram-Negative Bacteria

Area of Science:

• Microbiology
• Biotechnology
• Analytical Chemistry

Background:

• Differentiating Gram-negative and Gram-positive bacteria is crucial in biological science.
• Accurate bacterial identification underpins understanding of their characteristics and pathogenesis.
• Existing methods for bacterial differentiation can be time-consuming or require specialized equipment.

Purpose of the Study:

• To develop a novel aptasensor for the specific detection of Gram-negative bacteria.
• To integrate an anti-lipopolysaccharide (LPS) aptamer with a G-quadruplex-based DNAzyme for enhanced detection.
• To establish a spectroscopy-based method for efficient and straightforward Gram-negative bacterial identification.

Main Methods:

• The study designed an aptasensor combining an anti-LPS aptamer with a G-quadruplex-based DNAzyme.
• Spectroscopy was employed as the detection technique for LPS-containing bacteria.
• The aptasensor's performance was evaluated using Gram-negative bacteria, specifically *Escherichia coli*.

Main Results:

• The novel aptasensor successfully enabled spectroscopy-based detection of Gram-negative bacteria.
• The detection limit for *Escherichia coli* was determined to be approximately 2.7 × 10⁵ cells/mL.
• The developed aptasensor demonstrated efficiency and simplicity for laboratory use.

Conclusions:

• The developed aptasensor offers a promising tool for the rapid and specific identification of Gram-negative bacteria.
• Integration of aptamers and DNAzymes provides a sensitive platform for bacterial detection.
• This technology can streamline laboratory diagnostics for Gram-negative bacterial infections.