A novel Eu3+ doped polydopamine nano particles/reductive copper particle hydrogel-based ECL sensor for HPV 16 DNA detection

The novel Eu3+ doped polydopamine nanoparticles (PDA:Eu NPs)-based electrochemiluminescence (ECL) sensor had been constructed for HPV 16 DNA detection. As a kind of organic ECL nanoprobe, polydopamine nanoparticles (PDA NPs) had the characteristics of low toxic and adjustable ECL emission. In this work, we improved the optical performance of PDA NPs by Eu3+ doping. The incorporated Eu3+ has changed the energy level of PDA NPs. Due to the high oxygen affinity of Eu3+, 2.5-fold ECL enhancement of PDA:Eu NPs was achieved with the coreactant of H2O2. In order to improve the sensitivity of the sensor, the hydrogel with reductive copper Cu (I) particle was prepared and modified on the sensing platform. The Cu (I) particle-based hydrogel worked as catalyst to induce more OH, which further strengthened the ECL of PDA:Eu NPs. Finally, the DNA walker cycled sensing modified with T7 exonuclease was employed to detect HPV 16 DNA. The ECL signal had a linear relationship with the concentration of the target DNA ranging from 1 nmol/L to 100 nmol/L. And the LOD was 0.6 nmol/L. The PDA:Eu NPs/Cu (I) particle hydrogel-based biosensing system provided a new pathway in the ECL research.