Building Bridges to New Fluorophores

使用超出可见光范围的光对细胞和组织进行成像是有利的，因为 很少有内源分子能够吸收或发射这些更长的波长。这 导致较低的光毒性和较高的信噪比，因为光信号的衰减较小 自体荧光的干扰较小。在这个波长范围内合适的荧光染料有 长期以来一直以花菁为主，这是一类荧光团，通常光稳定性低，体积大 尺码。因此，在这个波长范围内开发更小和更稳定的染料是 非常可取。在这项建议中，我们将探讨电子给体的范围和纳入 在不同的位置和染料上降低流明取代，以优化紧凑的近红外为目标 用于广泛应用的荧光团、猝灭剂和荧光探头。

Imaging of cells and tissues using light beyond the visible range is advantageous because there are few endogenous molecules capable of absorbing or emitting at these longer wavelengths. This results in lower phototoxicity and higher signal-to-noise as there is less attenuation of the optical signal and less interference from autofluorescence. Suitable fluorescent dyes in this wavelength region have long been dominated by cyanines, a class of fluorophore that typically has low photostability and large size. The development of smaller and more photostable dyes in this wavelength region is therefore highly desirable. In this proposal, we will explore the scope of electron donors and the incorporation of LUMO-lowering substitutions in different positions and dyes, with the goal of optimized compact near-IR fluorophores, quenchers, and fluorogenic probes for a wide range of applications.