مشخصات پژوهش

Localized surface plasmon resonance (LSPR), strongly depends on the type, size, shape and refractive index of surrounding environment of nanoparticles. Asymmetric gold nanoparticles, such as gold nanorods (AuNRs) with their unique optical and electrical properties are suitable for various applications in environmental fields such as water and wastewater treatment [1], and sensors for detecting water pollutants [2]. In this study, a wet chemistry synthesis method was used for seed-growth. The seed solution was prepared by mixing (0.2 M CTAB 9.75 mL, 10 mM HAuCl4 250 μl , and 0.1 M NaBH4 600 μl), and then kept at room temperature. This product has a brownish yellow color. Then, the growth solution is prepared by mixing ( 0.1 M CTAB 9.5 mL, 10 mM AgNO3 120 μl, 10 mM HAuCl4 500 μl, 0.1 M ascorbic acid 110 μl ). Next, a 30 μl amount of pre-prepared seed solution is added to the growth solution and allowed to rest for 24 hours. The color of the solution changes from colorless to purple in a few hours. Finally, the absorbance spectra is taken after a day [3]. The absorbance spectrum of the synthesized AuNRs by grain-growth method is displayed in Fig. 1. Two plasmonic peaks at 520 nm and 770 nm were observed in the spectrum which is responsible for the purple color of the solution.