Fluorophore Questions

[KnowledgesSeeker]

Would a "non-fluorophore"  emit the same amount of light absorbed/not emit a photon after absorbing light? Basically, how would a non-fluorophore act differently from a fluorophore?
Also, do scientists use Stokes' shift to determine whether something will shine under a UV/Infrared light? If so, how exactly?
Why do fluorophores have to be cyclic/have high resonance energy?
Why do fluorophores bind to nucleic acids? I know they help detect stuff, but why would a nucleic acid anf fluorophore organically bind together?
Any responses to these questions would be great; I'm sorry if I used the wrong terminology — I'm not an expert.

[exchemist]

9 hours ago, KnowledgesSeeker said:

Would a "non-fluorophore"  emit the same amount of light absorbed/not emit a photon after absorbing light? Basically, how would a non-fluorophore act differently from a fluorophore?
Also, do scientists use Stokes' shift to determine whether something will shine under a UV/Infrared light? If so, how exactly?
Why do fluorophores have to be cyclic/have high resonance energy?
Why do fluorophores bind to nucleic acids? I know they help detect stuff, but why would a nucleic acid anf fluorophore organically bind together?
Any responses to these questions would be great; I'm sorry if I used the wrong terminology — I'm not an expert.

As I recall, when a non-fluorophore is excited by absorption of radiation, it can lose energy in a number of ways that are non-radiative. These will include collisional deactivation and also in some cases bond-breaking (e.g. if excitation is to a state involving a suitable antibonding orbital). I'm not sure I've seen the word "phosphorophore", but some molecules lose energy radiatively, not by fluorescence but via intersystem crossing to a triplet state, emission from which is known as phosphorescence rather than fluorescence. 

Conjugated organic molecules are far from the only compounds that can fluoresce*, but their extensively delocalised π-orbitals have fairly low lying excited states that often emit in the visible region of the spectrum without bond-breaking (the σ-bond will hold the molecule together when various π* modes are excited).    

Since the Stokes shift is something observed when a compound fluoresces, I'm not sure how it can be used to predict whether or not something will fluoresce.

I'm afraid I don't know anything about the use of fluorescent molecules in biochemistry (I'm sure others here may), but it is to be expected that some organic molecules may be able to bind to nucleic acids, so synthesising one containing a fluorophore is not hard to envisage in principle.  

 

*The word fluorescence comes from the visible glow from fluorite (CaF₂) when it contains certain impurities, under UV illumination. Many minerals fluoresce.

Edited May 30, 2022 by exchemist