Synergistic antimicrobial effects of polyaniline combined with silver nanoparticles

Abstract

Silver/polyaniline nanocomposites (Ag NPs/PANI) containing PANI nanofiber and Ag nanoparticles were synthesized by one-step approach without using any extra reducing agent or surfactant and applied to new antimicrobial agents. Morphologies and crystallinity of the nanocomposites were characterized with SEM and XRD. The results showed that the average diameter of the PANI nanofibers is around 50-150 nm, and the average particle size of Ag NPs is around 100 nm. The crystallinity of PANI gets better with increasing silver nitride concentration. UV-vis absorption spectroscopy analysis indicated that the Ag NPs have some effect on the microstructure of PANI. The antimicrobial properties of Ag NPs/PANI against Gram-negative Escherichia coli, Gram-positive Staphylococcus aureus and fungous Yeast were evaluated using viable cell counts. The test results demonstrated that Ag NPs/PANI have enhanced antimicrobial efficacy compared to that of pure Ag NPs or pure PANI under the same test condition. The mechanism of the synergistic antimicrobial effect of Ag NPs with PANI was also proposed. In addition, thermal gravity analysis indicated that pure PANI and Ag NPs/PANI exhibit better thermal stability.

Enhanced functionality of colloidal polyaniline/polyvinyl alcohol nanocomposite as an antibacterial agent

“…These results (Table 2) are consistent with previously reported data [13][14][15] showing that PAn has an intrinsic antibacterial effect.…”

“…Gizdavic-Nikolaidis et al [13] demonstrated that functionalized-based PAns are effective at inhibiting the growth of wild-type Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), and Staphylococcus aureus (S. aureus). Jia et al [14] reported that the combination of silver (Ag) nanoparticles and PAn has a synergistic antimicrobial efficiency on E. coli, S. aureus, and yeast bacteria. Jotiram et al [15] also reported antibacterial activity of PAnmupirocin nanocomposite against gram-positive and gram-negative bacteria, such as S. pyogenes, S. epidermidis, S. aureus, and E. coli.…”

Antibacterial and conductive injectable hydrogels based on quaternized chitosan-graft-polyaniline/oxidized dextran for tissue engineering

“…LC 50 of QCS40 for ADMSCs was 2670 µg/mL, which was about 3.7 times higher than that of QCS66 (720 µg/mL). Also, HC 50 of QCS40 was about 4 times higher than that of QCS66 (5000 µg/mL). Thus, we synthesized four different QCS-g-polyaniline copolymers with polyaniline weight percentages from 1%…”

“…QCS is more effective for killing S. aureus than E. coli bacteria, because the cell wall of S. aureus is fully composed of peptide polyglycogen while that of E. coli is made up of peptide polyglycogen and an outer lipopolysaccharide layer potential barrier against high molecular weight molecules [34]. In contrast to QCS, polyaniline is more effective in killing E. coli than S. aureus [50]. This is attributed to E. coli's multilayer structure cell wall.…”

“…Furthermore, some reports demonstrated that polyaniline possesses good antibacterial activity especially for gram-positive bacterium [48][49][50].…”