Preparation of Ordered Ag@Au Hybrid Nanotubes Arrays and their Fluorescence Enhancement of Poly(3-Hexylthiophene)

Ordered Ag@Au hybrid nanotube arrays were prepared by a galvanic replacement reaction and subsequently evaluated for their effectiveness as substrates for enhancing the fluorescence of poly(3-hexylthiophene) (P3HT). Ordered AgNWs arrays were assembled using a three-phase interface method, and ordered Ag@Au hybrid nanotube arrays were successfully prepared by a galvanic replacement reaction between a HAuCl 4 solution and ordered AgNWs arrays. The morphology of the ordered silver nanowires (AgNWs) arrays and Ag@Au nanotube arrays, as well as the influence of reaction time on the galvanic replacement reaction, were investigated. The fluorescence and laser-Raman properties of the conjugated polymer P3HT on various ordered Ag@Au nanotubes were analyzed. Gold (Au) particles grow on the surface of AgNWs, the diameter of the nanotubes gradually increases, and the ordered Ag@Au hybrid nanotubes form gradually. The surface plasmon resonance (SPR) peaks of Ag@Au hybrid nanotube arrays redshift and become wider as the reaction proceeds compared to AgNW arrays. The fluorescence properties of P3HT films on various ordered Ag@Au hybrid nanotubes were much higher than those on bare silicon substrates, but compared to the gold nanowire array, there is a decrease. As the galvanic displacement reaction progresses, the degree of reduction in fluorescence intensity increases. The unique aspect of this work was that the plasmon resonance wavelength of the ordered Ag@Au hybrid nanotube arrays showed a substantial redshift and broadening, which is much closer to biological samples. The ordered Ag@Au hybrid nanotube arrays can be used as ultra-sensitive fluorescence sensing platforms.