Tailored for Binding: Alanine‐Modified Poly(1‐Naphthylamine) Targets Serum Albumins

This study presents a new approach for modifying the structural and functional properties of poly(1‐naphthylamine) (PNA) by incorporating the amino acid alanine (Ala) in different molar proportions (80/20, 50/50, and 20/80 for PNA/Ala) through an ultrasound‐assisted polymerization process. The synthesized Ala‐modified PNA copolymers were comprehensively analyzed using Fourier‐transform infrared and ultraviolet–visible (UV–vis) spectroscopy, along with scanning electron microscopy (SEM). These techniques confirmed successful functionalization and revealed notable morphological changes as the alanine content increased. To assess their biointeraction behavior, the copolymers were tested for binding with bovine serum albumin (BSA) and human serum albumin (HSA) using fluorescence spectroscopy. The fluorescence emission spectra displayed pronounced quenching upon addition of the Ala/PNA materials, and Stern–Volmer analysis indicated a static quenching mechanism. The obtained binding constants (Kb≈10 5 L·mol −1 ) reflected strong affinities, particularly in samples with higher PNA ratios, emphasizing the influence of the π‐conjugated backbone on protein interactions. Molecular docking simulations further supported the experimental findings, revealing that hydrogen bonding and van der Waals forces predominantly stabilize the copolymer–protein complexes. Overall, the results demonstrate that amino acid‐functionalized conducting polymers, such as Ala/PNA, offer promising potential for creating biocompatible surfaces in biosensing and biomedical systems where controllable protein binding is a key requirement.