Electrode Surface Modification by a Spirobifluorene Derivative. An XPS and Electrochemical Investigation

Abstract

Ordered thin layers of a spirobifluorene derivative containing an amino group were formed by grafting them onto a self-assembled monolayer (SAM) of 11-mercaptoundecanoic acid (11-MUA) on gold. Either physical (H-bonding) or chemical bonding (activated by EDCl) was investigated. X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy confirmed that both methods can be used to effectively graft 2-amino-9,9‘-spirobifluorene molecules onto the SAM surface, giving high surface coverages, with a significantly higher packing in the case of chemisorbed films. EIS measurements also showed that the covalently bonded spirobifluorene SAMs act as an effective barrier to both ion penetration and heterogeneous electron transfer.

Aromatic and Aliphatic Thiol Self-Assembled Monolayers on Au: Anchoring and Delivering Copper Species

“…In this case water displacement could be the main mechanism operating in these SAMs because ligand displacement should reduce the amount of COO in relation to Cu, leading to values smaller than 2. The excess of COO can be explained considering free COO ions in equilibrium with the CuAc complex that can be incorporated since it is known that acetate ions are able to interact with pyridine and amine-terminated thiols. , …”

Synthesis, Characterization, and Electrochemiluminescence of Luminol‐Reduced Gold Nanoparticles and Their Application in a Hydrogen Peroxide Sensor

“…The N 1s spectra of both luminol and AuNPs ( Figure 4D and E, respectively) were curve-fitted into two components at 398.8 and 399.7 eV, attributed to the nitrogen atoms in the amine group (ÀNH 2 ) and amide group ( À CO À NH À ), respectively. [37,38] A large decrease in the relative content of the 399.7 eV component ( À CO À NH À ) demonstrated the relatively low content of luminol on the surface of the nanoparticles, as this component was particular www.chemeurj.org to luminol and the 398.8 eV component ( À NH 2 ) was mutual for both luminol and AP 2À . Notably, the N 1s spectrum of luminol-reduced AuNPs also confirmed the absence of the protonated state (ÀNH 3 + ) reported to be at approximately 402.3 eV.…”

Influence of Fluorene and Spirobifluorene Regioisomerism on the Structure, Organization, and Permeation Properties of Monolayers

“…19 This was accomplished by post-functionalization of a Self-Assembled Monolayers (SAMs) of acid-terminated alkanethiols on gold, forming either chemically bonded or physisorbed films. Even if SAMs are known from decades and allow the Page 3 of 36…”

“…To our knowledge, only one example in the literature describes the immobilization of SBF-based molecules into an ordered monolayer. 19 This was accomplished by postfunctionalization of a self-assembled monolayers (SAMs) of acidterminated alkanethiols on gold, forming either chemically bonded or physisorbed films. Even if SAMs are known for decades and allow the preparation of well-ordered and compact monolayer films, this approach could only be applied to few materials and mainly coinage metals.…”

“…These techniques offer a convenient way to immobilize SBF onto surfaces but lead to disordered multilayer films. To our knowledge, only one example in the literature describes the immobilization of SBF-based molecules into an ordered monolayer . This was accomplished by postfunctionalization of a self-assembled monolayers (SAMs) of acid-terminated alkanethiols on gold, forming either chemically bonded or physisorbed films.…”