Surfactant For Functionalization Of Nanomaterial And Its Performance Study

Surfactants are versatile amphiphilic molecules, and have been widely applied in the preparation of functional nanomaterials, and other areas. The functionalization of nanomaterials primarily achieved by controlling the morphology and size of nanomaterials or through the surface modification of nanomaterials. Gold nanorod as a kind of metal nanomaterials, their properties such as optical properties and toxicity strongly depend on aspect ratios and surface coatings. Currently, many strategies have been used to manipulate the aspect ratio of gold nanorods and modify the gold nanorods with biocompatible and functionalization-friendly stabilizers. However, no attentions were paid on the simultaneous size tuning and surface modification of gold nanorods. At the same time, as a kind of layered nanomaterial, montmorillonite is widely used in the fields such as catalysis, adsorption, and so on. However, the report of montmorillonite applied in the field of chemical luminescence was rare.In our studies, we use surfactants to functionalization the nanomaterials, including gold nanorods and montmorillonite. The properties such as stability, biocompatibility have been improved through the functionalization processes. The main research contents are as follows: (1) It is found that fluorosurfactants can act as an excellent candidate for other modification reagents for the modification of gold nanorods. In comparation with the cetyltrimethylammonium bromide coated gold nanorods, the fluorosurfactant coated gold nanorods show excellent biocompatibility, nontoxicity, and high stability. Meanwhile, fluorosurfactant ligands can etch gold nanorods to achieve tunable aspect ratios. Based on this, we report a flexible and simple procedure for size tuning and cetyltrimethylammonium bromide removal of gold nanorods using commercially available nonionic fluorosurfactants, enabling the conjugation of gold nanorods for specific targeting, uptake, and delivery.(2) Cationic surfactant-amplified chemiluminescence acts as a common technique for a variety of assays. By using ion exchange method, the cetyltrimethylammonium bromide interaction with the montomorillonite, realizing the functionalization. The functional montomorillonite can significantly amplify chemiluminescence from the peroxynitrite system compared with the cetyltrimethylammonium bromide only. The geometrical configuration of surfactant at the surface of montomorillonite is confirmed. In addition, the enhancement mechanism of cetyltrimethylammonium bromide-modified montomorillonite on the peroxynitrite chemiluminescence is discussed. The success of this work has broken the bottleneck of halide counterion-quenched chemiluminescence signals, and thus would broaden the application of cationic surfactant-amplified chemiluminescence.