Ultrasensitive sandwich-like electrochemical biosensor based on core-shell Pt@CeO2 as signal tags and double molecular recognition for cerebral dopamine detection

Abstract

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.