Tsen K T, Tsen Shaw-Wei D, Chang Chih-Long, Hung Chien-Fu, Wu T-C, Kiang Juliann G
Department of Physics, Arizona State University, Tempe, AZ 85287, USA.
Virol J. 2007 Jun 5;4:50. doi: 10.1186/1743-422X-4-50.
Resonant microwave absorption has been proposed in the literature to excite the vibrational states of microorganisms in an attempt to destroy them. But it is extremely difficult to transfer microwave excitation energy to the vibrational energy of microorganisms due to severe absorption of water in this spectral range. We demonstrate for the first time that, by using a visible femtosecond laser, it is effective to inactivate viruses such as bacteriophage M13 through impulsive stimulated Raman scattering.
By using a very low power (as low as 0.5 nj/pulse) visible femtosecond laser having a wavelength of 425 nm and a pulse width of 100 fs, we show that M13 phages were inactivated when the laser power density was greater than or equal to 50 MW/cm2. The inactivation of M13 phages was determined by plaque counts and had been found to depend on the pulse width as well as power density of the excitation laser.
Our experimental findings lay down the foundation for an innovative new strategy of using a very low power visible femtosecond laser to selectively inactivate viruses and other microorganisms while leaving sensitive materials unharmed by manipulating and controlling with the femtosecond laser system.
文献中曾提出利用共振微波吸收来激发微生物的振动状态，试图以此来消灭它们。但由于在此光谱范围内水的强烈吸收，将微波激发能量转移到微生物的振动能量上极其困难。我们首次证明，通过使用可见飞秒激光，利用脉冲受激拉曼散射可有效使诸如M13噬菌体等病毒失活。
通过使用波长为425nm、脉冲宽度为100fs的极低功率（低至0.5nj/脉冲）可见飞秒激光，我们发现当激光功率密度大于或等于50MW/cm²时，M13噬菌体被灭活。M13噬菌体的失活通过噬菌斑计数来确定，并且发现其取决于激发激光的脉冲宽度以及功率密度。
我们的实验结果为一种创新的新策略奠定了基础，即使用极低功率可见飞秒激光，通过飞秒激光系统进行操控和控制，选择性地使病毒及其他微生物失活，同时使敏感材料不受损害。
