Electrostatic Attachment of Gold and Poly(lactic acid) Nanoparticles onto ω‐Aminoalkanoic Acid Self‐Assembled Monolayers on 316L Stainless Steel

Abstract

The assembly of poly(lactic acid) (PLA) nanoparticles on a 12-aminodecanoic acid (ADA) self-assembled monolayer (SAM) is described. Assembly is accomplished through electrostatic interactions between the positively charged SAM and the negatively charged PLA nanoparticles. The strategy used involves two steps in which a preliminary electrochemical coating of the ADA SAM is followed by a second step that involves immersing the SAM in a solution containing gold or PLA nanoparticles. The SAM was characterized by using cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), FTIR spectroscopy, and contact angle measurements, whereas scanning electron microscopy (SEM) was used to image the nanoparticles after electrostatic attachment was achieved. We found that the surface coverage of the nanoparticles could be controlled by modulating the electrostatic interactions between the negatively charged particles and the positively charged SAM surface by varying the pH of the nanoparticle solution, the immersion time, and the number of cyclic voltammetry scans under which the SAM was formed.

In situ Electrochemical Impedance Spectroscopy of Electrostatically Driven Selective Gold Nanoparticle Adsorption on Block Copolymer Lamellae

“…Moreover, a significant difference in the AuNP packing density can be observed between 30% and 45% quaternized q P2VP domains, proving an increased AuNP adsorption with higher becoming θ quaternization . Similar results gained from resembling systems were reported by Cant et al, Lau et al, and Shustak et al Note here, that EIS measurements revealed each individual block copolymer film to require somewhat different durations to reach impedance equilibration upon the different fluid injections. However, impedance balancing is crucial to serve as reference point for following fluid injections and to ensure full charge neutralization at the film|electrolyte interface during AuNP solution injection as well as to observe significant distinctions in particle packing density after measurement.…”

Ferromagnetic Cobalt Nanoparticles and Their Immobilization on Monomolecular Films and Chemical Templates

“…Similar behavior was recorded for AUDT SAM, which was quite unexpected since the −NH 2 group is generally considered to be suitable to bind metal (e.g. Au) NPs by electrostatic attraction between the particles and film surfaces 52, 61. However, it appeared to be non‐effective for the binding of the Co NPs in the given case, even though the suspension of NPs was acidic and the terminal −NH 2 groups of the SAM could be protonated readily.…”

Gold Nanoparticle Patterning on Monomolecular Chemical Templates Fabricated by Irradiation-Promoted Exchange Reaction

“…The binding of the NPs to the AUDT-, TPDMT-, and PPPT-containing SAMs and chemical templates occurred over different mechanisms depending on the character of the terminal (tail) group. In particular, in the case of amino (AUDT) and pyridine (PPPT) termination, the NPs were presumably immobilized via electrostatic interaction . Indeed, the pH of the fabricated gold colloid solution was around 5, so that the amine and pyridine tail groups of the respective SAMs were expected to be protonated and thus carrying a positive charge when exposed to the suspension of NPs which in turn, as mentioned above, were charged negatively.…”