A dual-potential ratiometric electrochemiluminescence biosensor based on Au@CDs nanoflowers, Au@luminol nanoparticles and an enzyme-free DNA nanomachine for ultrasensitive p53 DNA detection

Herein, an amplified electrochemiluminescence (ECL) ratiometric biosensor for p53 DNA sequence assay was described based on [email protected] dots nanoflowers ([email protected]), [email protected] nanoparticles ([email protected]) as luminophors and an enzyme-free DNA walker for signal amplification. The ratiometric strategy endowed the sensor with a prominent accuracy. Taking advantage of DNA-walker signal amplification feature, a high sensitivity for target detection was achieved. Under the optimal conditions, the designed biosensor exhibited a lower limit of 0.34 fM and wide linear range from 1 fM to 10 pM for p53 DNA sequence detection. In particular, compared with traditional Ru(bpy)33+/Ru(bpy)32+ derivatives and semiconductor nanoparticles, [email protected] and [email protected] have the advantages of cost-effective, excellent biocompatibility, and easy labeling, which offered new opportunity for building ratiometric ECL biosensor platform.