Department of Physics, McGill University, 3600 University St., Montreal, QC H3A 2T8, Canada.
Anal Bioanal Chem. 2013 Jun;405(16):5431-40. doi: 10.1007/s00216-013-6985-z. Epub 2013 May 7.
The pigment hemozoin is a natural by-product of the metabolism of hemoglobin by the parasites which cause malaria. Previously, hemozoin was demonstrated to have a very high nonlinear optical response enabling third harmonic generation (THG) imaging. In this study, we present a complete characterization of the nonlinear THG response of natural hemozoin in malaria-infected red blood cells, as well as in pure isostructural synthesized hematin anhydride, in order to determine optimal imaging parameters for detection. Our study demonstrates the wavelength range for optimal pulsed femtosecond laser excitation of THG from hemozoin crystals. In addition, we show the hemozoin crystal detection as a function of crystal size, incident laser power, and the emission response of the hemozoin crystals to different incident laser polarization states. Our systematic measurements of the nonlinear optical response from hemozoin establish detection limits, which are essential for the optimal design of malaria detection technologies that exploit the THG response of hemozoin.
疟原虫代谢血红蛋白产生的色素血晶是一种天然的副产品。先前已经证明，血晶具有非常高的非线性光学响应能力，能够进行三次谐波产生（THG）成像。在这项研究中，我们全面描述了疟原虫感染的红细胞中天然血晶的非线性 THG 响应，以及纯同构合成的血红素无水物的非线性 THG 响应，以确定用于检测的最佳成像参数。我们的研究表明了从血晶晶体中进行 THG 的皮秒飞秒脉冲激光激发的最佳波长范围。此外，我们还展示了血晶晶体检测与晶体尺寸、入射激光功率以及血晶晶体对不同入射激光偏振态的发射响应之间的关系。我们对血晶的非线性光学响应进行了系统的测量，确定了检测极限，这对于利用血晶的 THG 响应来优化疟疾检测技术的设计是至关重要的。
