Magnetic fluorescent molecularly imprinted nanoparticles for detection and separation of transferrin in human serum

Transferrin (TrF) is an important glycoprotein and disease biomarker that controls iron ion balance in the human body. Isolation and detection of TrF have important implication for the early detection of disease. Thus, a magnetic fluorescent molecularly imprinted nanoparticles (FMINPs) was prepared for extraction and fluorescence detection of TrF. The FMINPs was prepared with two steps, the first step was the synthesis of magnetic TrF imprinted nanoparticle and the second step was introducing a near-infrared fluorescent compound (CyA) on the imprinted nanoparticles, which has a strong near infrared fluorescence emission at 730 nm while excitation at 690 nm and a large fluorescence signal quenching after adsorption of TrF. The concentration of TrF can be determined by the change of the fluorescence signal. FT-IR, TEM and fluorescence spectrophotometer were used to verify the successful preparation and the fluorescence performance of the FMINPs. Under the optimized experimental conditions, the prepared FMINPs had a great fluorescence performance, offering the lower relative standard deviation (7.7%), good analytical range (0.025-0.175 mg/mL, R-2 = 0.998) and lower detection limit (0.0075 mg/mL) for TrF. This method provides a new solution for the direct detection and separation of TrF in human serum samples.