Photoluminescence spectra of human serum albumen and morin embedded in porous alumina membranes with ordered pore arrays

For the first time, an organic dye, morin, and another bio-macromolecule, human serum albumen (HSA), were embedded in porous alumina (P-Al) fabricated by anodization in oxalic acid. The photoluminescent (PL) spectra of morin and morin-HSA immersed in the P-Al pores were measured and compared with those of liquid solutions. It was found that their PL positions are similar to those of dye-Al3+ in ethanol solution, and the PL of the embedded morin was greatly enhanced by the introduction of HSA. We have ascribed the appearance of PL bands to the formation of morin-Al complexes in the nanopores, with its inner wall being involved. A likely luminescence model was proposed to explain the observed PL enhancement due to the coexistence of morin and HSA in the nanopores, which has been proved by UV and Fourier transform infrared measurements. Moreover, the PL intensity increased with increasing pore diameter, which may be used to develop a luminescent array to predict the pore size of a P-Al layer.