Self‐assembled monolayers (SAMs) presenting carbohydrates (glycans) have been widely prepared on gold surfaces to mimic the carbohydrate surfaces that are involved in molecular recognition phenomena in living cells. The binding affinity of carbohydrate immbolized on SAM surfaces to various carbohydrate‐binding proteins (such as lectins) can be studied by optical, electrochemical, piezoelectrical and thermal sensing techniques. The lectins present on the surface of pathogens (e.g., bacteria or viruses) can be used as targets for capturing onto carbohydrates immobilized on SAM surfaces. The immobilized carbohydrates can also be used for detecting different types of disease biomarkers present in bodily fluids. Synergistic properties of carbohydrate SAMs and gold nanoparticles can be used for vaccine preparation and drug delivery. By studying different types of glycans, their properties, and the behavior toward recognition of specific pathogens and biomarkers, we can develop not only new therapeutics but also enhance the diagnostic strategies of various diseases. In this chapter, we discuss carbohydrate‐terminated SAMs and their common preparation strategies. Next, we focus on roles of different components of SAMs, characterization techniques, and applications.
Part of the book: Carbohydrate
Nanoporous gold (np-Au) has many interesting and useful properties that make it a material of interest for use in many technological applications. Its biocompatible nature and ability to serve as a support for self-assembled monolayers of alkanethiols and their derivative make it a suitable support for the immobilization of carbohydrates, enzymes, proteins, and DNA. Its chemically inert, physically robust and conductive high-surface area makes it useful for the design of electrochemistry-based chemical/bio-sensors and reactors. Furthermore, it is also used as solid support for organic molecular synthesis and biomolecules separation. Its enhanced optical property has application in design of plasmonics-based sensitive biosensors. In fact, np-Au is one of the few materials that can be used as a transducer for both optical and electrochemical biosensing. Due to the presence of low-coordination surface sites, np-Au shows remarkable catalytic activity for oxidation of molecules like carbon monoxide and methanol. Owing to the importance of np-Au, in this chapter we will highlight different strategies of fabrication of np-Au and its emerging applications based on its unique properties.
Part of the book: Noble and Precious Metals