Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
J Chem Phys. 2011 Jan 21;134(3):034511. doi: 10.1063/1.3518751.
Fundamental molecular selectivity limits are probed by exploiting laser-controlled quantum interferences for the creation of distinct spectral signatures in two flavin molecules, erstwhile nearly indistinguishable via steady-state methods. Optimal dynamic discrimination (ODD) uses optimally shaped laser fields to transiently amplify minute molecular variations that would otherwise go unnoticed with linear absorption and fluorescence techniques. ODD is experimentally demonstrated by combining an optimally shaped UV pump pulse with a time-delayed, fluorescence-depleting IR pulse for discrimination amongst riboflavin and flavin mononucleotide in aqueous solution, which are structurally and spectroscopically very similar. Closed-loop, adaptive pulse shaping discovers a set of UV pulses that induce disparate responses from the two flavins and allows for concomitant flavin discrimination of ∼16σ. Additionally, attainment of ODD permits quantitative, analytical detection of the individual constituents in a flavin mixture. The successful implementation of ODD on quantum systems of such high complexity bodes well for the future development of the field and the use of ODD techniques in a variety of demanding practical applications.
通过利用激光控制的量子干涉来创建两种黄素分子的独特光谱特征，探究基本的分子选择性极限。先前，通过稳态方法几乎无法区分这两种黄素分子。最优动态分辨（ODD）使用最佳形状的激光场来瞬态放大微小的分子变化，否则这些变化在使用线性吸收和荧光技术时将无法被注意到。通过将最佳形状的紫外泵浦脉冲与时间延迟、荧光耗尽的红外脉冲相结合，在水溶液中对核黄素和黄素单核苷酸进行分辨，实验证明了 ODD 的有效性，它们在结构和光谱上非常相似。闭环、自适应脉冲整形发现了一组紫外脉冲，它们会引起两种黄素的不同反应，并允许同时对黄素进行约 16σ的分辨。此外，ODD 的实现允许对黄素混合物中的各个成分进行定量、分析检测。在如此高复杂性的量子系统上成功实施 ODD，为该领域的未来发展以及在各种苛刻的实际应用中使用 ODD 技术奠定了良好的基础。
