Mechanisms of Thermal Decomposition of Organic Monolayers Grafted on (111) Silicon

The thermal stability of different organic layers on silicon has been investigated by in situ infrared spectroscopy, using a specially designed variable-temperature cell. The monolayers were covalently grafted onto atomically flat (111) hydrogenated silicon surfaces through the (photochemical or catalytic) hydrosilylation of 1-decene, heptadecafluoro-1-decene or undecylenic acid. In contrast to alkyl monolayers, which desorb as alkene chains around 300 °C by the breaking of the Si−C bond through a β-hydride elimination mechanism, the alkyl layers functionalized with a carboxylic acid terminal group undergo successive chemical transformations. At 200−250 °C, the carboxyl end groups couple forming anhydrides, which subsequently decompose at 250−300 °C by loss of the functional group. In the case of fluorinated alkyl chains, the C−C bond located between CH2 and CF2 units is first broken at 250−300 °C. In either case, the remaining alkyl layer is stable up to 350 °C, which is accounted for by a kinetic model involving chain pairing on the surface

Kinetics of Activation of Carboxyls to Succinimidyl Ester Groups in Monolayers Grafted on Silicon: An in Situ Real-Time Infrared Spectroscopy Study

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Highly sensitive and reusable fluorescence microarrays based on hydrogenated amorphous silicon–carbon alloys

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Active Acetylcholinesterase Immobilization on a Functionalized Silicon Surface

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Functionalized Silicon Surfaces for Biological and Chemical Sensors

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Semiquantitative Study of the EDC/NHS Activation of Acid Terminal Groups at Modified Porous Silicon Surfaces

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Functionalization of Azide-Terminated Silicon Surfaces with Glycans Using Click Chemistry: XPS and FTIR Study

Efficient functionalization of silicon substrates is important for the development of silicon-based sensors. Organic monolayers directly bonded to hydrogen-terminated silicon substrates via Si–C bonds display enhanced stability toward hydrolytic cleavage. Here, we show that monolayers presenting a high density of terminal azide groups are amenable to bioconjugation with alkynyl-derivatized glycans via a copper-catalyzed azide–alkyne 1,3-dipolar cycloaddition. The prerequisite azide-functionalized silicon surface is fabricated via hydrosilylation of undecylenic acid with hydrogen-terminated silicon substrate followed by reaction of the thus formed monolayer of acid groups with short, bifunctional oligoethylene oxide chains carrying an amine function at one terminus and an azido group at the other. The possibility to functionalize these azido-surfaces with alkynyl-derivatized glycans such as propargyl mannose through a click protocol is demonstrated and evidenced using X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. In addition, the interaction of these mannose-adorned silicon substrates with glycan binding proteins such as <i>Lens culinaris</i> lectin is investigated. The data establishes clearly the specificity of the interaction of this newly fabricated silicon surface for mannose-selective proteins as well as its reusability, thereby demonstrating its potential as a sensor

Molecular monolayers on silicon as substrates for biosensors

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