Inhibition of Sulfate‐Reducing Bacteria by Para‐amino‐N‐((1‐Alkylpyridin‐1‐Ium Bromide)‐4‐Yl) Benzamide Surfactants and Surfactant‐Coated Silver Nanoparticles

Abstract

In the present work, we report the antibacterial activity of silver nanoparticles (AgNP) coated with the surfactants para‐amino‐N‐((1‐decylpyridin‐1‐ium bromide)‐4‐yl) benzamide and para‐amino‐N‐((1‐dodecylpyridin‐1‐ium bromide)‐4‐yl) benzamide (P10 and P12, respectively). P10 and P12‐coated AgNP were stable, as confirmed by ultraviolet–visible spectrophotometry, transmission electron microscopy, and other surface activity parameters. Both P10 and P12 and the coated AgNP formulations were investigated for their activity against sulfate reducing bacteria (SRB). Overall, our results showed the importance of coating AgNP with surfactants (P10 and P12) in the design and development of new biocides against SRB.

Antibacterial and Anticandidal Activity of the Nanostructural Composite of a Spirothiazolidine-Derivative Assembled on Silver Nanoparticles

“…Therefore, the presence of alkyl chains (hexadecyl) in compound P16 enhanced the stability of the AgNPs. It was concluded that the alkyl chain length provided a physical barrier, preventing aggregation between the surfaces of AgNPs during collisions, in addition to the effect of P16 molecules on the charge of AgNPs; that is, the P16 reduced the surface charge of the AgNPs [ 40 ]. These factors led to an overall reduction in the aggregation of AgNPs, as shown in Figure 3 .…”

“…Moreover, the SEM image in Figure 3 gives an indication about the aggregation of the Ag-nanoparticles which were produced as a result of the surface plasmon charges on the silver nanoparticles. It is known that metal particles in colloidal solution usually have a negative charge due to adsorbed anions; this leads to more aggregation of such particles in solution, as shown in Figure 3 [ 40 ]. Further investigation of the nanostructure of the P16 capped AgNPs ( P16-AgNPs ) is summarized in Figure 3 .…”

“…Further investigation of the nanostructure of the P16 capped AgNPs ( P16-AgNPs ) is summarized in Figure 3 . It was noted from previous publications that the aggregation of the nanoparticles can be weakened by mixing with neutralized molecules such as P16 , as these neutralize the adsorbed ions and reduce the charge on the particles, thereby preventing the particles from aggregating with each other [ 40 ]. The SEM images in Figure 3 reveal the formation of nanoshells of P16 after capping with AgNPs.…”

“…An Ag-nanoparticle colloidal solution was synthesized using the chemical reduction method shown in previous publication [ 40 ]. Briefly, 0.01 g AgNO 3 was placed in 50 mL of distilled water the solution was boiled to 100 °C.…”

“…The crude precipitate was recrystallized twice from methanol to yield 5-Amino-3-(4-fluorophenyl)-Nhexadecyl-7-(4-methylphenyl)-2-H-spiro[cyclohexane-1,2'- [1,3]thiazolo [4,5-b]pyridine]-6-carbonitrile (P16) in the form of brown crystals (yield 80%; m.p. 131-133 • C) [40].…”