What Makes Thienoguanosine an Outstanding Fluorescent DNA Probe?

Thienoguanosine (thG) is an isomorphic guanosine (G) surrogate that almost perfectly mimics G in nucleic acids. To exploit its full potential and lay the foundation for future applications, 20 DNA duplexes, where the bases facing and neighboring thG were systematically varied, were thoroughly studied using fluorescence spectroscopy, molecular dynamics simulations, and mixed quantum mechanical/molecular mechanics calculations, yielding a...