Aptamer-controlled peroxidase activity of platinum nanoparticles/Fe-MOF nanozyme for highly effective voltammetric detection of carcinoembryonic antigen

Carcinoembryonic antigen (CEA) is the most widely adopted biomarker for the early determination of various cancers, thus it is very important to design a simple and highly effective sensing method to detect CEA. Herein, by synthesizing Fe-MOF nanohybrid loaded with platinum nanoparticles (Pt NPs/Fe-MOF) nanozyme and selecting CEA aptamer (Apt) as the specific recognition element, a simple nanozyme-based voltammetric sensor was designed to detect CEA based on Apt-controlled the catalytic activity of Pt NPs/Fe-MOF nanozyme. The as-synthesized Pt NPs/Fe-MOF nanozyme could catalyze effectively 1,2-diaminobenzene oxidation to produce electroactive 2,3-diaminophenazinc (DAP) which can exhibit a strong reduction current. Nonetheless, when Pt NPs/Fe-MOF is covered fully by Apt of CEA, the peroxidase activity of the as-synthesized Pt NPs/Fe-MOF nanozyme is remarkably restricted and the peak current of DAP would disappear nearly. Interestingly, this catalytic activity could be recovered effectively in the presence of CEA owing to the specific identification of Apt toward CEA. Through optimizing several experimental factors, the as-designed nanozyme voltammetric sensor offers superior detective performance for CEA. In addition, the as-designed sensor possesses superior specificity and selectivity, reproducibility and stability as well as practical applications, showing great potentials for achieving simple, sensitive and highly effective determination of CEA.