A Theoretical Study of One- and Two-Photon Activity of D-Luciferin

• Main Authors: Mausumi Chattopadhyaya, Md. Mehboob Alam
• Format: Article
• Language: English
• Published: MDPI AG 2016-11-01
• Series: Computation
• Subjects: two-photon absorption; solvent effect; channel interference; computational chemistry; non-linear optics; few-state model; response theory; TD-DFT
• Online Access: http://www.mdpi.com/2079-3197/4/4/43

In the present work, we have theoretically studied the one and two-photon absorption (OPA and TPA) probabilities of the native D-luciferin molecule and attempted to find the origin of its larger TPA cross-sections in polar solvents than in non-polar ones. The calculations using state-of-the-art linear and quadratic response theory in the framework of time-dependent density functional theory using hybrid B3LYP functional and cc-pVDZ basis set suggests that two-photon transition probability of this molecule increases with increasing solvent polarity. In order to explicate our present findings, we employed the generalized few-state-model and inspected the role of different optical channels related to the TPA process. We have found that the two-photon transition probability is always guided by a destructive interference term, the magnitude of which decreases with increasing solvent polarity. Furthermore, we have evaluated OPA parameters of D-luciferin and noticed that the the excitation energy is in very good agreement with the available experimental results.