Preparation of titanium ion functionalized polydopamine coated ferroferric oxide core-shell magnetic particles for selective extraction of nucleotides from Cordyceps and Lentinus edodes.

In this study, a titanium ion (Ti) functionalized polydopamine coated ferroferric oxide (FeO@PDA@Ti) core-shell magnetic particle was prepared for the selective extraction of nucleotides. Firstly, different metal ions including Ti, Zr, Fe, Al, Cu, Zn, Ni and Mg were respectively immobilized onto FeO@PDA particles and their extraction efficiency for five nucleotides [cytidine-5'-monophosphate (CMP), uridine-5'-monophosphate (UMP), guanosine-5'-monophosphate (GMP), thymidine-5'-monophosphate (TMP) and adenosine-5'-monophosphate (AMP)] were compared. Among these prepared materials, FeO@PDA@Ti, which exhibited the highest extraction efficiency for nucleotides, was further characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. After being optimized of the extraction parameters including adsorbent amounts, extraction time, extraction temperature, type and concentration of the eluent, the prepared FeO@PDA@Ti magnetic particles were successfully applied for the selective extraction and determination of CMP, UMP, GMP, TMP and AMP in Cordyceps and Lentinus edodes. Good linearity (varying from 0.063 to 19.000 μg/mL, R > 0.999) and low limit of detection (LODs) (ranging between 0.0047 and 0.0141 μg/mL) for target analytes were achieved. These results demonstrated that the synthesized material in this study had potential for selective extraction of phosphorylated small molecular compounds in complicated matrix.