Ferrites–bismuth ferrite is an intriguing option for medical diagnostic imaging device due to its magnetoelectric and enhanced near-infrared fluorescent properties. However, the embedded XFO nanoparticles are randomly located on the BFO membranes, making implementation in devices difficult. To overcome this, we present a facile bio-approach to produce XFe2O4–BiFeO3 (XFO–BFO) (X = Cr, Mn, Co, or Ni) membranes using Shewanella oneidensis MR-1. The perovskite BFO enhances the fluorescence intensity (at 660 and 832 nm) and surface potential difference (−469 ~ 385 meV and −80 ~ 525 meV) of the embedded spinel XFO. This mechanism is attributed to the interfacial coupling of the X–Fe (e− or h+) and O–O (h+) interfaces. Such a system could open up new ideas in the design of environmentally friendly fluorescent membranes.