Background:Nanoparticles (NPs) are biosynthesized using various bacteria. Luminescent bacteria emit light as the result of oxidation of fatty aldehydes by the enzyme luciferase. The bacterial luciferase plays a key role in emitting light and most probably in biosynthesis of NPs. In this work, we demonstrated that proteins related to luminescence enzymatic activity were most probably mounted on NPs by comparison of NPs before (S1) and after (S2) heat treatment. Methods: TiO2 NPs was synthesized using a green method mediated Vibrio VLA strain. Briefly, the cell free extract of VLA was prepared and TiO(OH)2 solution was added. The precipitate was dried and a part of the prepared powder was heated in an oven at 350 ℃ for comparison characteristic. The samples were characterized by XRD, FTIR, FESEM, and fluorescent microscopy. The luminescence activity of samples were studied using luminometer. Results:The XRD patterns of samples showed diffraction peaks that were attributed to anatase phase. The FTIR spectra of S1 showed the peaks around 3300, 1640, 1500, and 1071 cm-1 attributed to the primary and secondary amines groups. The FESM image showed the spherical morphology and the average particle size 11.95 and 13.07 nm for S1 and S2, respectively. The EDX analysis showed C and N peaks for S1 that were attributed to existence of enzymes. But these peaks were removed for S2. The S1 solution had fluorescent property most probably due to existence FMN. The suspension of S1 emitted light up to 4000 RLU/s by adding decanal. Conclusion: The important Vibrio VLA proteins with fluorescent properties were immobilized on TiO2 NP sample and showed interesting properties.

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