Magnetic Nano Sensor Particles with Luminescence Up-conversion Capability

联合研究项目旨在研究用于光学、化学和生化传感的多功能纳米颗粒。结合在一个纳米粒子中的有益功能包括：磁性、发光上转换、传感和光收集。这些传感器粒子受到近红外(NIR)光的激发。产生的反斯托克斯磷光用于激发指示剂或标记染料，从而能够检测化学参数和生物测定的性能。近红外激发和上转换效应不会引起生物样品的背景发光。这些纳米传感器颗粒可以很容易地从样品中分离出来，并通过磁场在不同的位置收集。由于在这一点上发光标签的浓度很高，所以该“原位”传感器斑点导致了灵敏度的增强。传感器是通过发光寿命测量来读出的，这是有利的，因为它们实际上与整体信号强度无关。由于上转换纳米晶体(UPCON)的寿命很长，所以所需的仪器很简单。将磁性纳米晶和纳米碳管包裹在聚合物基质中，可制得多功能纳米粒子。根据应用情况，将研究普通粒子和核壳粒子。多功能粒子的表面含有羧基，可在水样中获得稳定的悬浮液，并与受体、配体、酶或荧光指示剂偶联以引入传感功能。此外，高度创新的点击化学方法将被应用于将这些功能分子连接到表面。或者，聚合物核或壳将掺杂荧光指示剂染料，以引入对化学参数的敏感性。纳米传感器将用于监测生物膜和细胞培养的关键参数氧气和pH值，并使用抗体和DNA寡聚体进行模型亲和结合分析。这两个小组的专门知识和互补专长将在该项目中得到充分利用。

The joined research project aims to investigate multi-functional nanoparticles for optical chemical and biochemical sensing. The beneficial functionalities combined in one nano particle include: magnetism, luminescence up-conversion, sensing and light harvesting. These sensor particles are excited with near-infrared (NIR) light. The anti-Stokes phosphorescence generated is used to excite an indicator or label dye enabling the detection of chemical parameters and the performance of bioassays. The NIR excitation and the up-conversion effect do not induce background luminescence of the biological sample. These nanosensor particles can be easily separated from the sample and collected at distinct positions by magnetic fields. This “in-situ” sensor spot leads to a sensitivity enhancement due to the high concentration of luminescent label at this point. The sensors are read-out by luminescence lifetime measurements, which is advantageous, because they are virtually independent of the overall signal intensity. The necessary instrumentation is simple due to the long lifetime of the up-conversion nanocrystals (upcon NCs). Multifunctional nano-particles will be prepared by entrapping magnetic nanocrystals and upcon NCs in the polymeric host matrix. Depending on the application, plain and core-shell particles will be investigated. The surface shell of the multifunctional particles contains carboxyl groups to obtain stable suspensions in aqueous samples and to conjugate receptors, ligands, enzymes or fluorescent indicator dyes to introduce the sensing function. In addition, the highly innovative click-chemistry approach will be applied to conjugate these functional molecules to the surface. Alternatively, the polymeric core or shell will be doped with fluorescent indicator dyes to introduce sensitivity to chemical parameters. The nano sensor will be applied to monitor the key parameters oxygen and pH of bio-films and cell cultures and to perform model affinity binding assays using antibodies and DNA oligomers. The specialized and complementary expertises of the two groups will be fully exploited within this project.