DaCosta Matthew V, Doughan Samer, Han Yi, Krull Ulrich J
Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road, Mississauga, ON L5L 1C6, Canada.
Anal Chim Acta. 2014 Jun 17;832:1-33. doi: 10.1016/j.aca.2014.04.030. Epub 2014 Apr 22.
Through the process of photon upconversion, trivalent lanthanide doped nanocrystals convert long-wavelength excitation radiation in the infrared or near infrared region to higher energy emission radiation from ultraviolet to infrared. Such materials offer potential for numerous advantages in analytical applications in comparison to molecular fluorophores and quantum dots. The use of IR radiation as an excitation source reduces autofluorescence and scattering of excitation radiation, which leads to a reduction of background in optical experiments. The upconverting nanocrystals offer excellent photostability and are composed of materials that are not particularly toxic to biological organisms. Excitation at long wavelengths also minimizes damage to biological materials. In this review, the different mechanisms responsible for the upconversion process, and methods that are used to synthesize and decorate upconverting nanoparticles are presented to indicate how absorption and emission can be tuned. Examples of recent applications of upconverting nanoparticles in bioassays for the detection of proteins, nucleic acids, metabolites and metal ions offer indications of analytical advantages in the development of methods of analysis. Examples include multi-color and multi-modal imaging, and the use of upconverting nanoparticles in theranostics.
通过光子上转换过程，三价镧系元素掺杂的纳米晶体将红外或近红外区域的长波长激发辐射转换为从紫外到红外的更高能量发射辐射。与分子荧光团和量子点相比，此类材料在分析应用中具有诸多潜在优势。使用红外辐射作为激发源可减少自发荧光和激发辐射的散射，从而降低光学实验中的背景。上转换纳米晶体具有出色的光稳定性，且由对生物有机体毒性不大的材料组成。长波长激发还能将对生物材料的损伤降至最低。在本综述中，介绍了负责上转换过程的不同机制以及用于合成和修饰上转换纳米颗粒的方法，以说明如何调节吸收和发射。上转换纳米颗粒在蛋白质、核酸、代谢物和金属离子检测的生物测定中的近期应用实例，展示了其在分析方法开发中的分析优势。实例包括多色和多模态成像，以及上转换纳米颗粒在诊疗中的应用。
