Study Of SERS-active Substrate Based On Capillary

Surface Enhanced Raman Spectroscopy (SERS), as a new type of detection method, has been used extensively in the field of chemistry and biochemistry duo to its low limit of detection (LOD), indeed to single molecule detection. Accordingly, SERS is a hot topic in the scientific research and much hard work has been done in the past,mainly on the study of the theory of SERS and the synthesis of SERS active substrates. At the present time, electromagnetic enhancement and chemical enhancement are the main mechanisms of SERS accepted by all the people. On the other hand, from broadening out materials of SERS, preparing high sensitivity, high reproducibility and high stability of SERS substrates to studying multifunctional SERS substrates, a great of research achievements are made on synthesis of SERS substrates. Nowadays, the loading of SERS substrates are not limited to a piece of glass or Si wafer, but other loads such as metal/metal oxide, paper, capillary and so on. In a word, SERS has been applied extensively in society. However, there are also many problems to be solved.In recent years, as the demand of SERS applied on spot, it is necessary to be easier to carry and preserve for SERS substrates, and the most important problem of the traditional SERS substrates is that they need the help of extra instrument, for example, a pipet. In this paper, we have prepared a new type of SERS substrate based on capillary due to the advantages of easy-carrying, preservation and self-sampling. The detailed researches are summarized as follows:1. A SERS-active substrate based on capillary was obtained with a simple method. A capillary was employed here to serve as a self-sampling system duo to its capillary action. First, inner wall of the capillary was decorated with a layer of amino group by immersing the capillary into an ethanol solution of3-aminopropyltrimethoxysilane (APTMS). Then, the suspension of Gold nanoparticles would be easily flow into the inner capillary because of its capillary force. Thus, AuNPs will adhere to the inside surface of capillary. The SERS activity of AuNPs coated capillary strongly depended on the concentration of Au suspension. The SERS-active substrate we have obtained could be used in detection of Thiram on spot without the help of extra instrument due to its capillary force.2. TiO2nanotubes arrays decorated by AgNPs was obtained with a simple method and served as a recyclable SERS substrate. The results showed that the temperature had no effect on the morphology of ZnO nanorod arrays, and the SERS substrate showed good SERS performance and recyclability.3. TiO2nanotubes arrays decorated by AuNPs on the inner wall of capillary was synthesized in a two-steps method. The SERS substrate showed good sensitivity, stability, reproducibility and well-recycled performance.