Development of optically bright nanotags for SERS

表面增强拉曼散射是一种非常灵敏和选择性的技术，是一种迅速崛起的用于超灵敏分析的有效方法。它提供了比普通拉曼散射更强的增强，因此是检测痕量分析物的理想选择，而且由于获得了分子特定的光谱，所以它是检测混合物中分析物的理想选择。表面增强拉曼散射的灵敏度也有助于对信号进行隔离检测，这是因为可以从专门合成的标记以及商业上可用的标记中获得强烈的信号。这些标签与纳米颗粒相结合，可以用作编码标签，因为它们独特的振动光谱允许在诸如饮料市场的品牌保护等领域对产品进行标记。该项目建议开发使用785 nm或更高的激发波长进行编码纳米颗粒检测所需的技术和标签。这将需要合成不同类型的金属纳米颗粒，这些纳米颗粒对电磁纳米颗粒的红外区域具有吸收作用，并为纳米颗粒开发涂层，以保护它们免受强酸等恶劣环境的影响，同时仍然能够提供强烈的SERS响应。然后，我们将开发制造和优化纳米颗粒的方法，以尽可能提供最强(最亮)的SERS信号。这可能需要分离程序，例如使用简单的流体或分离系统，将最亮的纳米颗粒与较弱的SERS活性较弱的纳米颗粒分开，以丰富SERS响应。纳米粒子最有可能被二氧化硅取代，以使它们保持很强的SERS活性，并对它们作为标签的环境保持稳定。然后，我们将使用这些明亮的、环境稳定的纳米颗粒来检测医疗保健环境中的整个细菌。

Surface enhanced Raman scattering is an extremely sensitive and selective technique that is rapidly emerging as an effective method for ultrasensitive analysis. It offers an increased enhancement over normal Raman scattering therefore is ideal for the detection of trace amounts of analyte and because of the molecularly specific spectra obtained it is ideal for detecting analytes in mixtures. The sensitivity of SERS also lends itself to stand off detection due to the intense signals which can be obtained from specially synthesised labels as well as ones which are commercially available. These labels, in combination with nanoparticles, can be used as coded labels due to their unique vibrational spectra allowing labelling of products in areas such as brand protection for example in the beverage market.This project proposes to develop the technique and labels required to carry out detection of coded nanoparticles using an excitation wavelengths of 785 nm or higher. This will require synthesising different types of metal nanoparticles which have absorbances towards the infrared region of the electromagnetic nanoparticles and developing coatings for the nanoparticles that would protect them from harsh environments such as strong acid, while still being able to give a strong SERS response. We will then develop ways to make and optimise the nanoparticles to give the strongest (brightest) SERS signal possible. This may require separation procedures, for example using simple fluidics or separation systems, to separate the brightest nanoparticles from ones that are more weakly SERS active to enrich the SERS response. The nanoparticles will be cpated with, most likely, silica to allow them to remain strongly SERS active and stable to the environment in which they will act as a label. We will then use these bright, environmentally stable nanoparticles for the detection of whole bacteria in the healthcare environment.