An analog of graphene, graphitic carbon nitride (g-C3N4), is a promising metal-free conjugated polymer, owing to its excellent performance in biosensing and photocatalysis. We have demonstrated the adsorption of twenty-five amino acids (AA) employing DFT-D3 correction method of Grimme's dispersion and the non-equilibrium Green's function (NEGF) for describing the coherent transport in molecular devices coupled with adsorption energies, substrate-adsorbate distances, the density of states, charge transfer mechanism, molecular dynamics, work function, and bonding patterns. We have also depicted the current-voltage (I–V) characteristics where the curves of current vs. bias voltage (I–Vb) display a distinct response for each AA. Furthermore, we have illustrated the anti-bacterial mechanism of g-C3N4 utilizing bioinformatics study and compared it with DFT studies. We found evidence of a difference in transport, electronic as well as molecular mechanisms reinforcing the possibility of g-C3N4 applications based on sensors for AA sequencing of proteins, water-disinfection technique, and microbial control.