Ultrasensitive sandwich-like electrochemical biosensor based on core-shell Pt@CeO₂ as signal tags and double...

In this report, 4-mercaptophenylboronic acid (MBA) and dithiobis (succinimidyl propionate) (DSP) were used as DA molecular recognizer, which bounded onto the prepared Pt@CeO₂ nanomaterial and the electrode surface. A sandwich-like electrochemical biosensor was constructed for sensitive detection of dopamine (DA) based on double molecular recognition and Pt@CeO₂ (MBA-DSP- Pt@CeO₂) as an electrochemical probe for signal amplification. It is worth noting that the diol and amine groups of DA were reacted by the boronic acid of MBA and the succinimide residue of DSP, respectively. This sandwich-like double molecular interaction can efficiently and accurately identify DA. The uniform Pt@CeO₂ multicore@shell nanospheres as signal tags and signal amplifiers in electrochemical biosensor were synthesized by hydrothermal, which has excellent catalytic activity for H₂O₂. Interestingly, more oxygen vacancies were produced in the lattice structure of CeO₂ doped with Pt, so that the catalytic and redox performance of the obtained Pt@CeO₂ was much better than that of pure CeO₂, thus greatly improving the performance of the proposed sensor. The proposed electrochemical biosensor provided a wide detection range of 2-180 nM and a low detection limit (0.71 nM) by the electrochemical measurement. And it also showed ultra-high sensitivity, accuracy and broad application prospect, which developed a new research method for early clinical diagnosis.