Study Of Molecular Adsorptive Law Of Benzene Derivatives Adsorbed On Silver Nano-Particles By Sers

Surface-Enhanced Raman Scattering (SERS) is such an effective technology that has shown great advantages in high sensitivity and high quenching of fluorescence. It is a powerful utility in studying the surface characteristic of the substrates and the surface configuration of the adsorbates. Silver colloidal particle is nanometer-size particle, so it has many advantageous characteristics differing from other traditional bulk materials. Therefore, the SERS technology with the silver nano-particles as the SERS-active substrate has been widely applied in many fields, such as biology, physics, chemistry, material and so on. Thus, it is fairly significant using the SERS technology to detect the adsorptive behavior of the molecules with representative configuration, to acquire the factors influencing the molecules' adsorptive behavior and to grasp the general adsorptive law of representative molecules adsorbed on the surfaces of silver nano-particles, which is very helpful to further study SERS mechanism and to further extend SERS application.The vibrational enhancement of molecules lies on the adsorptive behavior of the molecules adsorbed on the metal surfaces. While the most two important factors that could influence the molecules' adsorptive behavior are the surfaces characteristic of the SERS-active substrates and the surface configuration of the adsorbate molecules. Though there have been some discussions in this aspect, most of them concentrate on the study of certain specific application details. The systemic and general experiment analyses as well as the theoretical instruction are very scarce in the study of the adsorptive behavior's variation of the molecules with representative configurationadsorbed on the different characteristic substrates. In our study, a lot of work was done in these aspects:1. The general analytical methods were summarized.2. On the base of preparing method of silver aqueous colloid as SERS substrate, a new substrate-preparing method was developed, which is the dried filter paper filtrated with silver nano-particles. This method is very simple and effective and the enhancement factor of it is higher than silver aqueous colloid.3. A series of di-substituted benzenes (hydroxybenzoic acids and aminobenzoic acids etc.) and nitrogen-mixed benzoic acids with three kinds o f substituted configurations were employed a s adsorbates. T he v ariation o f molecular adsorptive b ehavior on the surface of silver nano-particles was studied in two circumstances of aqueous solution and dried silver-filtrated filter paper, as well as the variation of molecular adsorptive behavior with the number of silver particles on filter paper.4. To the molecules mentioned above, it is studied how the different electron effect of different substituted group on benzene ring influences the SERS effect of molecules adsorbed on the silver surfaces and how different substituted configuration of the same group on benzene ring influences the SERS effect and adsorptive geometry of molecules adsorbed on silver surfaces.Through the study mentioned above, a series of meaningful results was obtained as well as some general laws. Some parts of our work have been published on Journal of Colloid and Interface Science and Spectrochimica Acta part A.