Heptamethine Cyanine (Cy7) are a class of polymethine dyes that absorb light in the near-infrared (near-IR; 750-900 nm) region. This region is of great biomedical interest because light penetrates deeper into tissues due to reduced absorption and scattering by the tissue. Cy7 fluorophores can be conjugated to biomolecules such as carbohydrates, lipids, nucleic acids, and proteins.  An ideal Cy7 fluorophore should exhibit high photostability and minimal aggregation in aqueous solutions. However, Cy7 tends to aggregate due to π-π stacking of its symmetrical fluorophores, which can quench fluorescence and result in low signal-to-background ratios. There are limited methods to synthesize non-aggregating Cy7. Consequently, there is an urgent and unmet need to construct a general synthetic scheme for non-aggregating Cy7. We hypothesized that unsymmetrical heptamethine cyanines could help prevent pi-pi stacking and inhibit aggregation. To test this hypothesis, we modified the polymethine chain (composed of alternating dienes) by introducing a phenyl group at the C4’ (symmetrical) and C3’ (unsymmetrical) positions to create a novel Cy7 dye. We evaluated the photophysical properties (absorbance, emission, quantum yields, and photostability) of these modified dyes in organic solvents and aqueous buffer solutions. We have developed a general method for synthesizing Cy7 fluorophores. We conducted bioconjugation experiments using the NHS ester conjugating it to lysines of IgG1 at pH 8.5 at varying concentrations. The degree of labeling (DOL) ranged from 1 to 8 and increased with higher equivalents of the unsymmetrical dye. These results demonstrate, for the first time, that unsymmetrical Cy7 fluorophores do not aggregate in aqueous conditions and that the unsymmetrical dye can be effectively used for protein labeling. Our findings suggest that this novel approach to designing unsymmetrical Cy7 fluorophores could be extended to other polymethine fluorophore systems, potentially advancing the development of more stable and effective dyes for various biomedical applications.