<p>Hydrogels are multidimensional polymeric frameworks that consist of hydrophilic group segments. In addition to having an abundance of ionic and non-ionic functional components that can absorb or retain ionic dyes from sewage, hydrogels unique structure makes it easier for solutes to diffuse into the interior network. The primary objective of the present investigation intended to develop a series of pH-sensitive bio polymeric hydrogels based on citric acid and 1,4 butanediol through solventless, eco-friendly condensation polymerization. The structural and surface morphological characteristics were investigated by FT-IR, ¹H, ¹³C NMR spectroscopy and Scanning electron microscope (SEM) respectively. The thermal properties of the hydrogel have been studied using thermogravimetric analysis. The Swelling equilibrium studies were performed at various pH (2.0–11.0). Malachite green oxalate was chosen as the prototypical cationic dye. Batch adsorption experiment is employed to evaluate the dye removal efficiency of hydrogels. The computational studies involves the approach of DFT, Molecular docking and predicting the ADMET properties to examine the synthetic compound’s mechanism of interactions with drugs. Molecular docking studies suggest that this compound well interacts with three distinct poses of bacterial protein residues namely, Gyr A and two poses of Gyr B. The binding efficiency of Gyr B is greater than Gyr A. It is evident from ADMET characteristics that the compound can effectively deliver the drug across the blood-brain barrier. The synthesized hydrogels serve as sustainable and efficient adsorbents for the removal of toxic dyes from wastewater, driven by their high porosity and functional group interactions. Their versatility further extends to biomedical applications, where computational approaches provide deeper molecular insights.</p>