fig2

Figure 2. Fe/Fe₃O₄-based nanobiosensor for matrix metalloproteinase 1 detection. Consensus sequence GAGVPMS-MRGGAG. TCPP: tetrakis-carboxyphenyl-porphyrin. Scheme 1. A: Design principles of a nanobiosensor for protease detection. Consensus sequence: GAGVPMS-MRGGAG (MMP1); The average distance between fluorophore TCPP (tetrakis-carboxyphenyl-porphyrin) and Fe/Fe₃O₄ nanoparticle and FRET-acceptor cyanine 5.5 increases upon cleavage of the oligopeptide tether by a suitable protease, leading to an increase in fluorescence; B: TEM and HRTEM of dopamine-coated Fe/Fe₃O₄ core/shell nanoparticles; C: Typical emission spectra occurring from the nanosensor for MMP 13 after 1 h of incubation at 37 °C (λ_exc = 421 nm). low: buffer; middle:nanosensor; high: nanosensor after incubation with MMP13^[4].