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Over the past few decades the fabrication of nanoscale materials for use in chemical sensing, biomedical and biological analyses has proven a promising avenue. Nanomaterials show promise in such chemical and biological analysis mainly due to their highly tunable size- and shape-dependent chemical and physical properties. Furthermore, they exhibit unique surface chemistry, thermal stability, high surface area and large pore volume per unit mass that can be exploited for sensor fabrication. This review will discuss the chemical and physical properties of nanomaterials necessary for use as chemosensors and biosensors. It will also highlight some noteworthy recent avenues using nanoscale materials as scaffolds for chemosensing and biosensing. Nanomaterials that have proven to be useful for the fabrication of sensors, as reviewed herein, have compositions including metals, metal oxides, chalcogenides and polymers. Their structures range from nanoparticles, nanorods, and nanowires to nanoporous and core-shells. Examples of the different types of structures and compositions as well as sensors and biosensors fabricated from them will be described. Some nanomaterials are functionalized with various kinds of ligands and bioactive groups to produce sensitive and selective sensors for specific analytes. The combination of two or more types of nanostructures with core-shell type nanoassemblies and other composite structures, in addition to advantageous features enhancing sensitivity and response time of related sensors, are also discussed. [ABSTRACT FROM AUTHOR]

Aggregation of proteins in tissues is associated with several diseases, including Alzheimer's disease. It is characterized by the accumulation of amyloid β peptide (Aβ) in the extracellular spaces of the brain cells, resulting in neuronal death and other pathological changes. α-Crystallin, a small heat-shock protein in lens, and a peptide chaperone having the functional site sequence DFVIFLDVKHFSPEDLTVK of αA-crystallin may inhibit Aβ fibrillogenesis and toxicity. The peptide chaperone (mini-αA-crystallin), having an Aβ interacting domain and a complex solubilizing domain, was shown in previous studies to prevent aggregation of several proteins under denaturing conditions. In this in vitro study, using transmission electron microscopy and thioflavin T binding assay, we show that mini-αA-crystallin arrests the fibril formation of Aβ peptides. Mini-αA-crystallin also suppresses the toxic action of Aβ on rat pheochromocytoma (PC12) cells. The wide chaperoning capability of the peptide and its ability to inhibit amyloid fibril formation and suppress toxicity suggest that mini-αA-crystallin may serve as a universal chaperone in controlling diseases of protein aggregation, including Alzheimer's disease. (Mol Cell Biochem 267: 147–155, 2004) [ABSTRACT FROM AUTHOR]