Single-stage in situ synthesis of silver nanoparticles in antibacterial self-assembled overlays

Abstract

In this work, a novel single-stage process for in situ synthesis of Ag nanoparticles (NPs) using the layer-bylayer (LbL) technique is presented. The Ag NPs were formed into nanotextured coatings based on sequentially adsorbed poly(allylamine hydrochloride) (PAH) and SiO 2 NPs. Such highly porous surfaces have been used in the fabrication of highly efficient ion release films for applications such as antibacterial coatings. In this approach, the amino groups of the PAH acted as reducing agent and made possible the in situ formation of the Ag NPs. This reduction reaction occurred during the LbL process as the coating was assembled, without any further step after the fabrication and stabilization of the multilayer film. Biamminesilver nitrate was used as the Ag + ion source during the LbL process and it was successfully reduced to Ag NPs. All coatings were tested with gram-positive and gram-negative bacterial cultures of Escherichia coli, Staphylococcus aureus, and Lactobacillus delbrueckii showing an excellent antimicrobial behavior against these types of bacteria (more than 99.9% of killing efficiency in all cases).

Effect of both protective and reducing agents in the synthesis of multicolor silver nanoparticles

“…The control of their size and shape is a challenging goal, and a large number of reports have been published for the preparation of metal nanoparticles of various morphologies [1-5], mainly for plasmonic and sensing applications [6]. Very recently, our group has incorporated silver nanoparticles (AgNPs) in polymeric films for detecting fast changes of humidity (human breathing) [7,8] and, at the same time, preventing the growth of bacteria very likely in high-humidity atmosphere [9-11]. …”

Design of Nanostructured Functional Coatings by Using Wet-Chemistry Methods

“…Urrutia et al [93] fabricated nanotexturized coatings which have been tested in bacterial cultures of genus Lactobacillus, showing a good antimicrobial behavior against this type of bacteria. Based on the same hypothesis of nanotexturized coating by using the LbL is presented by the same author (Urrutia et al) [94]. In this work, in situ synthesis of Ag NPs into LbL films is obtained by the sequential deposition of poly(allylamine hydrochloride) (PAH) and SiO 2 NPs.…”

“…Long-term stability [92] Silica nanoparticles combined with a high surface area Lactobacillus plantarum Layer-by-layer assembly [93] In situ synthesis of silver nanoparticles Escherichia coli, Staphylococcus aureus and Lactobacillus plantarum Layer-by-layer technique [94] Size control…”

Layer-by-Layer Nano-assembly: A Powerful Tool for Optical Fiber Sensing Applications

“…An important consideration related to the LbL technique is that it can be implemented on a wide variety of different materials (not only polyelectrolytes), making possible the fabrication of advanced LbL coatings. According to this, a wide number of scientific research papers based on the incorporation of metal nanoparticles [51,52,53,54,55], carbon nanotubes [56,57], metallic oxide nanoparticles (silica, titania) [58,59,60,61,62], organic dyes [63], polypeptides [64], proteins [65,66], DNA [67], dendrimers [68], or quantum dots [69,70], among others, can be found in the literature. A representative example of this high versatility is shown in Figure 5 where two different chemical approaches denoted as the in situ synthesis (ISS) process and LbL embedding (LbL-E) deposition technique are used for the incorporation of metallic silver nanoparticles (AgNPs) into LbL films [71].…”