Polymers that efficiently interrelate with biological systems have fascinated a lot of curiosity in biosensor application. In order to determine their suitability and conducting abilities, the nature of ground state, excited states properties and binding affinities of such systems must be known. The vertical singlet-triplet gap, electronic transitions of 3-methyl-pyrrole-1-carboxylic acid has been studied using Spin-Flip Time density Functional Theory (SF-TDDFT) method with 6-311++G(d,p) basis set. All calculations were carried out using quantum mechanical softwares. Results revealed the Highest Occupied Molecular Orbital (HOMO) energies vary within the range of -5.22 to -6.24, while Lowest Occupied Molecular Orbital (LUMO) energies vary (from -0.62 to -1.84). Result revealed that the singlet-singlet transition for 3, 4 and 5 rings of MPC basically involves four (|H >, |H-1 >, |L > and |L+1 >) transitions. Result show a non-zero transition dipole moment (dnm) for MPC monomer and tetramer (Allowed transition), while dnm decreases for trimer, dimer and pentmer, due to the triple integral returning an ungerade (odd) product and redistribute electrons within the same orbital and will return a zero product.