pH在生物体系中起着调节细胞代谢和周期等极为重要的作用，因此实现对生理环境pH的有效监测具有重要的生物医学意义。近红外表面增强拉曼光谱（NIR SERS）标记在细胞标记、成像和pH传感等方面具有很大的潜力。然而，当前的“金属-染料-保护壳”型NIR SERS探针存在着制备难、成本高、毒性大和无法实现pH检测的缺点。本项目在前期研究基础上，提出一种新颖的“金属-拉曼活性保护壳”型探针。选用聚苯胺为低毒性NIR活性分子，既作为拉曼报道分子又作为金属保护壳，探索一种操作简单、价格低廉、生物相容性好且具有pH传感能力的NIR SERS探针的制备方法，并将此探针应用于细胞的pH监测。

It is of vital importance to effectively monitor the physiological pH, because pH plays a significant role in many cellular processes including cellular metabolism, cell cycle, proliferation and division. Near-infrared surface-enhanced Raman scattering (NIR SERS) probes exhibit great potentials for cell labeling, imaging and pH biosensing. However, current NIR SERS probes with “metal-dye-protective shell” type have many disadvantages, such as difficulty for preparation, high-cost, low-biocompatibility and inability for pH sensing. On the basis of previous studying, we propose fabrication of a novel NIR SERS probe with “metal-Raman active protective shell” type. Biocompatible polyaniline (PANI) serving as the NIR-active molecule is used as both the Raman reporter and the protective shell. And a simple and low-cost strategy is planed to be developed for fabrication of PANI-based NIR SERS probe with the capability of pH sensing. Finally, the application of this novel NIR SERS probe for pH biosensing will be carried out.