Surface Chemistry and Spectroscopy of Amyloid β (1-42) Mixed with and Conjugated to Quantum Dots Langmuir Monolayer

Nanoparticle chemistry is emerging in the field of nanomedicine and nanodiagnostics. In recent times quantum dots have been considered as potential probes for bioimaging. These particles can be beneficial when it comes to study neurodegenerative diseases such as Alzheimer's disease. Amyloid beta (1-42) (A beta (1-42)) is a polypeptide that is the major constituent of the plaques in Alzheimer's disease patients. We have examined the surface and spectroscopic properties of A beta (1-42) mixed with or conjugated to dihydrolipoic acid- and poly(ethylene glycol)-capped CdSe/ZnS quantum dots. Surface pressure-area isotherms and in situ UV-vis absorption and fluorescence spectroscopy were used to characterize the A beta (1-42) mixed with or conjugated to quantum dots at the air-water interface. The capping of quantum dots played a role in surface chemistry as was determined by surface pressure-area isotherms and spectroscopic properties of the Langmuir monolayer.