Preparation and Interfacial Properties of Phosphonic Acid-Terminated Self-Assembled Monolayers on Gold Surface

Abstract

The preparation and interfacial properties of self-assembled monolayers (SAMs) of 3-mercaptopropylphosphonic acid [HS-(CH 2 ) 3 -PO 3 H 2 , MPPA] adsorbed on Au surfaces have been systematically investigated with the electrochemical method, X-ray photoelectron spectroscopy (XPS), and surface-enhanced internal reflection infrared spectroscopy measurements. An improved rinse method (base-acid rinse protocol) is presented to prepare the MPPA monolayers free of unbound MPPA thiols. Experimental results show that the effect of the degree of dissociation of -PO 3 H 2 groups on the compactness of MPPA-SAMs is nonlinear possibly because of hydrogen bond interaction and the dibasic nature and hydrophilicity of the -PO 3 H 2 groups. The effects of pH and the electric field on the surface charge of MPPA-SAMs are investigated.

Potentiostatic infrared titration of 11-mercaptoundecanoic acid monolayers

“…These results can be classified into two groups. The first group [8][9][10][11][12][13] displays an increase of the monolayer acidity as the potential is made more positive (in agreement with predictions from electrostatic models [17][18][19]), whereas the second group [14][15][16] shows the opposite trend (which has been rationalized in terms of a cation-exchange model [14][15]). The potential-induced ionization of 11-mercaptoundecanoic acid (MUA) monolayers has been reported to display both of these opposite trends, under the scrutiny of different experimental techniques and in the presence of different electrolyte solutions.…”

“…Usually, this control is exerted through the solution pH, but attachment of the thiol group to a metallic substrate opens the possibility of applying a potentiostatic control on the ionization degree of the terminal carboxylic groups. Evidence supporting the influence of the substrate potential on the acid dissociation of thiol monolayers has been gathered from a variety of techniques, including voltammetric [8][9][10][11][12], surface Raman [13], quartz microbalance [14] and infrared absortion [15,16] experiments. These results can be classified into two groups.…”

Mercaptophosphonic acids as efficient linkers in quantum dot sensitized solar cells

“…53 In the case of nanowires, the dissolution is face-sensitive and more rapid than in case of bulk at lms. [54][55][56][57][58] For comparison, 2-mercaptopropionic acid (MPA) was also studied. 1): 2-mercaptoethylphosphonic acid (MEPA) and 11-mercaptoundecylphosphonic acid (MUPA).…”

Facile controlled preparation of phosphonic acid-functionalized gold nanoparticles

“…In the previous works [15][16][17][18][19][20][21][22][23][24][25], the phosphonic acid-functionalized planar gold have been constructed by using APO 3 H 2 -terminated thiols molecules, and consequently applied in various fields such as bioelectrochemistry [15][16][17][18][19][20]26], electroanalysis [23], ZrP materials [22], biomimetic membranes [24], oriented nucleation of minerals [27]. Meanwhile, there are also a few studies dedicated to exploring the preparation and property of the phosphonic acid-functionalized Au-NPs by using APO 3 H 2 -terminated thiols molecules [6,28].…”