Synthesis of gold nanoparticles/polyaniline boronic acid/sodium alginate aqueous nanocomposite based on chemical oxidative polymerization for biological applications.

Abstract Gold nanoparticles/polyaniline boronic acid/sodium alginate aqueous nanocomposite ((PABA-SAL)@AuNPs) was fabricated. Aniline boronic acid (ABA) served as reductant of gold salt, all within the SAL solution. While ABA reduced gold salt to its nanoparticles, the ABA monomer was also oxidized to its conducting polymeric form (PABA). The presence of PABA in the reaction mixture exerted solubility and stability challenge, thus SAL was used as stabilizer and solubilizer for PABA. The numerous cis-diol groups of SAL could bind to boronic acid groups of PABA to furnish PABA-SAL repeating polymer structure for AuNPs anchoring. Sparkling ruby red (PABA-SAL)@AuNPs have absorption peaks at 529 and 718 nm. Average particle sizes of nanocomposite were within 15–20 nm, with hydrodynamic diameter of 48.6 ± 0.9 nm, zeta potential of −32.5 ± 1.6 mV and conductivity value of 2015.3 ± 3.2 μS/cm. (PABA-SAL)@AuNPs possessed antibacterial activities against seafood associated bacterial isolates, with MIC and MBC ranging from 4 to 8 μg/mL. The moderate antioxidant capacity of (PABA-SAL)@AuNPs was observed, without any deleterious damages on human red blood cells. It also has good biocompatibility on Caco-2 and RAW 264.7, with cell viability not less than 70%. These results confirm the high prospect of (PABA-SAL)@AuNPs for possible biomedical applications.