Nguyen, T. V.; Vu, C. D.; Pham, T. B.; Pham, V. H.; Bui, H.; Vu, T. H. H.; Pham, V. H. Detection of Ultra-Low Concentration of Methylene Blue by Porous Silicon Photonic Crystals Covered With Siver Nanoparticles As Efficient Sers Substrate. Comm. Phys. 2021, 31, 381.