Ultrasmooth gold surfaces prepared by chemical mechanical polishing for applications in nanoscience.

For over 20 years, template stripping has been the best method for preparing ultrasmooth metal surfaces for studies of nanostructures. However, the organic adhesives used in the template stripping method are incompatible with many solvents, limiting the conditions that may subsequently be used to prepare samples; in addition, the film areas that can be reliably prepared are typically limited to ∼1 cm(2). In this article, we present chemical-mechanical polishing (CMP) as an adhesive-free, scalable method of preparing ultrasmooth gold surfaces.

The unusual self-organization of dialkyldithiophosphinic acid self-assembled monolayers on ultrasmooth gold.

We report the formation and characterization of self-assembled monolayers (SAMs) of dialkyldithiophosphinic acid adsorbates [CH3(CH2)n]2P(S)SH (R2DTPA) (n = 5, 9, 11, 13, 15) on ultrasmooth gold substrates prepared by the template stripping method. The SAMs were characterized using X-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, contact angle measurements, lateral force microscopy, and electrochemical impedance spectroscopy. The data show these SAMs exhibit an unusual trend in alkyl chain crystallinity; SAMs formed from adsorbates with short alkyl chains (n = 5) are ordered and crystalline, and the alkyl groups become increasingly disordered and liquidlike as the number of methylene units is increased.

Influence of alkyl chain length on the structure of dialkyldithiophosphinic acid self-assembled monolayers on gold.

We report the formation and characterization of self-assembled monolayers (SAMs) based on dialkyldithiophosphinic acid adsorbates {[CH(3)(CH(2))(n)](2)P(S)SH (n = 5, 9, 11, 13, 15)} on gold substrates. SAMs were characterized using X-ray photoelectron spectroscopy, reflection-absorption infrared spectroscopy, contact angle measurements, and electrochemical impedance spectroscopy. Data show that there is a roughly 60:40 mixture of bidentate and monodentate adsorbates in each of these SAMs.

New dialkyldithiophosphinic acid self-assembled monolayers (SAMs): influence of gold substrate morphology on adsorbate binding and SAM structure.

We report the fabrication and characterization of new self-assembled monolayers (SAMs) formed from dihexadecyldithiophosphinic acid [(C(16))(2)DTPA] molecules on gold substrates. In these SAMs, the ability of the (C(16))(2)DTPA headgroup to chelate to the gold surface depends on the morphology of the gold substrate. Gold substrates fabricated by electron-beam evaporation (As-Dep gold) consist of ∼50-nm grains separated by deep grain boundaries (∼10 nm).