Thiol-functionalised surface

Antifouling activity is one of the most important properties that catheters should ideally exhibit in order to prevent catheter-associated infections. To quantitatively investigate bacterial fouling on polymer-coated silicone rubber surfaces, the number of viable bacterial cells on the surfaces was measured [102]. After 1 day of incubation, there was a high number of viable Staphylococcus aureus and Escherichia coli cells on both pristine and thiol-functionalised surfaces (Staphylococcus aureus 8.8 and 8.6 log colony forming units (CFU), respectively Escherichia coli 8.5 and 8.2 log CFU, respectively) (Figure 6.1). 

Pristine PDMS silicone and thiol-functionalised surfaces, and surfaces coated with the two polymers, were tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. With the pristine surface serving as the control, the killing efficiency of the thiol-functionalised surface and surfaces coated with the two copolymers was studied. The number of Staphylococcus aureus in solution decreased slightly when the solution was incubated with the thiol-functionalised... 

A version of AFM is chemical force microscopy (CFM), where an AFM tip is coated with a thin chemical layer that interacts selectively with the different functional groups exposed on the sample surface. For example, gold-coated tips functionalised with a thiol... 

Nano-HAp was surface-treated with PMOEP in order to introduce phosphate-containing functional groups which were subsequently bonded to ethylene diamine-functionalised PLLA scaffolds or imbedded into PLLA scaffolds during fabrication. A grafting from approach made it possible to modify the surface of nano-HAp crystals. Thiol-functionalized HAp nanocrystals were used in the grafting polymerization of MOEP (unpurified). The results indicated that the PMOEP-grafted HAp nanocrystals exhibited increased colloidal stability in water. These modified nano-HAp particles were subsequently used for the fabrication of nanocomposite scaffolds. ... 

Figure 5.23 (a) A schematic example of a derivatised ferrocene thiol attached to a gold electrode. (b) A schematic highlighting that multiple-functionalised nanoparticles can be attached to a large surface to produce a highly sensitive device. J. J. Davis, Interfacial sensing surface-assembled molecular receptors, Chem. Commun, 2005, 3509-3513. Reproduced by permission of The Royal Society of Chemistry. 

SAMs consisting of a mixture of non-fimctionalised aUcanethiols and co-functionalised alkanethiols provide the chance to study isolated functionalised sites in SAMs. In these mixed SAMs the non-functionalised alkanethiols serve as dummy molecules to dilute the fimctionalised compounds and to isolate the active sites in order to minimise their interactions. These mixed SAMs play an important role, e.g. in the development of biorecognition surfaces [137-139). One obstacle in producing mixed monolayers is the different rate of adsorption of the non-functionalised and the end-fimctionalised thiols. Consequently, the final composition of the mixed SAMs not only depends on the initial ratio of the two thiols but also on their individual as well as cooperative adsorption and desorption kinetics [140]. Another problem is the tendency for similar molecules to aggregate into islands on the surface (Fig. 15) [141,142[. Therefore, the final SAM composition caimot be predicted easily. 

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