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

Differentiating bacteria into Gram-negative and Gram-positive categories is a standard method of identification in biological science and is essential for understanding bacterial characteristics. This study presents a novel aptasensor that integrates an anti-lipopolysaccharide (LPS) aptamer with a G-quadruplex-based DNAzyme. This aptasensor enables spectroscopy-based detection of LPS-containing Gram-negative bacteria. With a detection limit of approximately 2.7 × 10⁵ cells/mL for Escherichia coli, this aptasensor offers an efficient and straightforward solution for laboratory detection of Gram-negative bacteria.