Hollow fiber-supported graphene oxide molecularly imprinted polymers for the determination of dopamine using HPLC-PDA

Molecularly imprinted polymers (MIPs) of dopamine (DA) were constructed on the surface of graphene oxide (GO), and attached inside the pores of hollow fibers (HFs) for the solid-phase microextraction (SPME) of DA. Scanning electron microscopy, thermogravimetric analysis and Raman spectroscopy indicated that GO-MIP composites were successfully synthesized and modified in the pores of HFs via ultrasonication. Compared with common HFs and HFs modified with non-imprinted polymers (GO-NIP/HF) using the same SPME procedures, the GO-MIP/HF composites showed the best efficiency for the extraction of DA. The selectivity of GO-MIP/HF was investigated based on the selectivity factor (F) using epinephrine and norepinephrine as the structural analogues of DA. The linear range of dopamine was 1.05 × 10^-3 to 5.27 × 10^-3 μmol mL^-1, using this process with a detection limit of 2.64 × 10^-4 μmol mL^-1. The extraction procedure based on GO-MIP/HF was successfully used for the determination of DA in human serum and its hydrochloride injection, showing average recoveries of 83-96%. GO-MIP/HF was a good carrier for the selective adsorption of DA, and showed promise for the preconcentration of DA in real samples.