Dna ink - near-field absorption coupling for colorimetric detection, dna ink, chromic photoswitches, and chromic molecular ruler

A color changeable chromophore ink, comprising:

• at least one chromophore;
• at least one nucleotide oligomer, wherein said chromophore is bound to said nucleic acid strand;
• and
• a vehicle.

A chromic photoswitch composition for changing the emission behavior of an exciton, comprising:

• an input chromophore;
• a second chromophore;
• a third chromophore;
• a fourth chromophore;
• a first nucleotide oligomer;
• and
• a second nucleotide oligomer,
• wherein said input, second, and third chromophores are bound to said first nucleotide oligomer, wherein said input chromophore is placed between said second and said third chromophores, and wherein said input, said second, and said third chromophores are more than 2 nm apart,
• wherein said fourth chromophore is bound to said second nucleotide oligomer, wherein said second nucleotide oligomer is a complement to said first nucleotide oligomer,
• wherein said second chromophore has a similar absorption-emission behavior to said input chromophore,
• wherein said third chromophore has a different absorption-emission behavior different from said input chromophore,
• wherein said fourth chromophore when brought close to said input chromophore though binding of said first and said second nucleotide oligomers will electronically couple with said input chromophore, wherein said electronical coupling creates and recombines an exciton with an interaction energy that differs from the exciton of said second chromophore, and
• wherein said third chromophore has a similar absorption-emission behavior to said recombined exciton of said input and said fourth chromophores.