Peroxidase mimicking DNAzyme and Au-luminol supported biosensor for electrochemiluminescent detection of DNA

A simple and sensitive method was developed for the electrochemiluminescence (ECL) determination of DNA. • Au-luminol NPs addressed the issues of weak solubility and ECL signals of luminol in neutral conditions. • The target DNA induced the formation of heme and G-quadruplexes as biomimetic enzymes, thereby enhancing the electrochemical luminescence intensity of luminol. A novel signal amplification approach was developed for DNA detection, leveraging the synergistic effect of G-quadruplex/hemin DNAzyme and gold nanoparticles (Au NPs) to enhance the electrochemiluminescence (ECL) of luminol. The optimized system exhibited excellent linear response toward target DNA with a linear detection range from 10 fM-50 pM and achieved fM-level DNA detection. The spiked recoveries of serum samples ranged from 95.1% to 107.6%, demonstrating its reliable performance for practical sample analysis. Compared with recently reported analogous ECL sensors for DNA detection, this system featured a wider linear range, lower limit of detection and stronger anti-matrix interference capability, offering a new strategy for rapid and ultrasensitive detection of target analytes in complex matrices. Download: Download high-res image (235KB) Download: Download full-size image