Design and synthesis of Fe3O4@Au@cyclodextrin-molecularly imprinted polymers labeled with SERS nanotags for ultrasensitive detection of transferrin

As an important clinical biomarker, transferrin (TRF) plays an indispensable role in the function regulation of human body and its concentration reflects the occurrence of some diseases. Herein, a sensor based on magnetic molecularly imprinted polymers (MMIPs) and surface-enhanced Raman scattering (SERS) was developed for the sensitive detection of TRF. For this purpose, Fe3O4@Au@cyclodextrin-MIPs were successfully synthesized using β-cyclodextrin as the functional monomer because its appropriate size, hydrophobic cavities, and hydroxyl groups benefitted anchoring TRF through noncovalent interactions. An appropriate hydrophilic imprinted layer was generated by self-copolymerization of dopamine and m-aminophenylboronic acid (APBA). After TRF was captured by Fe3O4@Au@cyclodextrin-MIPs, it was labeled with 4-mercaptophenylboronic acid-modified AgNPs as SERS nanotags to construct a sandwich structured sensor. This MMIP-SERS sensor behaved excellent identification and detection performances toward TRF since Fe3O4@Au@cyclodextrin-MIPs contributed to high specificity of the assay and SERS provided high sensitivity. Furthermore, the reliability and feasibility of the sensor in real serum samples were verified by determining TRF from liver disease patients, suggesting its great potential in clinical TRF detection.