Peptide immobilisation on porous silicon surface for metal ions detection

In this work, a Glycyl-Histidyl-Glycyl-Histidine (GlyHisGlyHis) peptide is covalently anchored to the porous silicon PSi surface using a multi-step reaction scheme compatible with the mild conditions required for preserving the probe activity. In a first step, alkene precursors are grafted onto the hydrogenated PSi surface using the hydrosilylation route, allowing for the formation of a carboxyl-terminated monolayer which is activated by reaction with N-hydroxysuccinimide in the presence of a peptide-coupling carbodiimide N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide and subsequently reacted with the amino linker of the peptide to form a covalent amide bond. Infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy are used to investigate the different steps of functionalization

Positive and negative photopatterning of metal oxides on silicon via bipolar electrochemical deposition

Negative and positive microscale patterning of metal oxides is efficiently and rapidly carried out on flat Si(100) surfaces via a simple white light assisted bipolar electrochemical process.open113sciescopu

Preparation and functionalization of hydride terminated porous germanium

Porous germanium (PG) is prepared by a novel bipolar electrochemical etching (BEE) technique; scanning electron microscopy (SEM) clearly reveals formation of a porous layer up to a few microns thick that is Ge-H-x terminated as indicated by FTIR spectroscopy; the hydride terminated PG material is quite resistant to oxidation, even under thermal conditions, but can be induced to undergo hydrogermylation reactions with alkenes and alkynes.X1137sciescopu

Effects of organic monolayer formation on electrochemiluminescence behavior of porous silicon

The effects of various organic monolayers on the surface of porous silicon on the electrochemiluminescence (ECL, also referred to as electroluminescence in the literature) characteristics were investigated. Surfaces were terminated with alkyne, alkene, and alkyl functionalities through cathodic electrografting (CEG), Lewis acid-mediated hydrosilylation (LA), and anodic electrografting (AEG), respectively. ECL was induced through the known formic acid/sodium formate electron injection system. Alkyl-terminated surfaces produced through AEG yielded the brightest emission of any of the functionalized surfaces although ECL emission was about half as intense as that from the underivatized Si-H-terminated surface. The lifetime, however, was extended by a factor of 2, and these surfaces demonstrate an unprecedented recharging phenomenon. When ECL ceases, a brief 10 s application of a cathodic bias restores most of the ECL emission intensity. This process can be cycled about 10 times, and results in a substantially greater light output than that from any of the surfaces examined here, including the Si-H-terminated surface. Dodecenyl-terminated surfaces, produced through Lewis acid-mediated hydrosilylation of 1-dodecyne, show the greatest lifetimes, an order of magnitude longer than that of an Si-H-terminated surface, but their emission intensity is unfortunately very low. The induction times for light emission to occur decreased for all the functionalized surfaces, as compared to the native Si-H surface. Explanations for the effects of organic monolayer formation on ECL observed here are described.X112324sciescopu

Controlled electroless deposition of noble metal nanoparticle films on germanium surfaces

Thin noble metal films have been prepared as a result of the immersion of germanium substrates into dilute, aqueous solutions of AuCl4-, PdCl42-, or PtCl42-, respectively. Deposition proceeds via galvanic displacement in the absence of fluoride, pH adjusters, complexing agents, or external reducing agents. This manner of metal deposition serves as a cost-effective, high-throughput methodology with control over surface morphology and deposition rate by modulation of plating parameters such as concentration, temperature, and immersion time.X11160169sciescopu

Electroless nanoparticle film deposition compatible with photolithography, microcontact printing, and Dip-Pen nanolithography patterning technologies

Nanoparticles of Au, Pd, and Pt form spontaneously as thin, morphologically complex metallic films upon various semiconducting or metal substrates such as Ge(100), Cu, Zn, and Sri, via galvanic displacement from aqueous metal salt solutions. Patterning of these high surface area metal films into ordered structures utilizing photolithography, microcontact printing (mu-CP), and dip-pen nanolithography (DPN) is demonstrated on flat Ge(100), and (for mu-CP) on rough Zn foil.X11108115sciescopu

Best Practices for New Polymers and Nanoparticulate Systems How Not To Be Soft with Reporting Standards

International audienceSoft materials include a broad swath of flexible or deformable molecules, polymers, gels, colloids, and composites, many of which are inspired or derived from natural systems and materials. Due to the myriad of applications, from organic electronics to biomedical applications, these materials are of great interest to the materials chemistry community. We have contributed to an ongoing series of editorials and perspectives on best practices to help outline the basic information and data needed to properly report many flavors of new materials and devices, but this will be the first for new polymers and soft nanoparticle-based materials. The goal is to be constructive, and thus eliminate frustration of both authors and reviewers, and to help clarify the standards necessary for publishing in Chemistry of Materials