Facile fabrication of biocompatible metal-phenolic based nanoplatform for magnetic resonance-photoacoustic dual-mode imaging

The construction of a real-time and accurate diagnosis nanoplatform is an attractive prospect for precise cancer therapy. Herein, based on the gentle ion exchange reaction between Fe(III) and sodium alginate (SA), as well as the convenient selfassembly of Fe(III) and tannic acid (TA), an economical nanoprobe (SA and TA coordinate with Fe(III), denoted as ST-Fe) was constructed via a one-pot method. As natural biomolecules, SA and TA can effectively improve the biosafety of ST-Fe. More importantly, the introduction of SA has greatly improved the dispersion of ST-Fe, and significantly made its absorption peak red shift. These leaded it had good photoacoustic (PA) imaging effects at 900 nm. Additionally, ST-Fe exhibited a good magnetic resonance (MR) imaging signal. Thus, ST-Fe showed superior performance as a PA/MR imaging dual-mode contrast agent for the diagnosis of tumors.