With this award from the Chemistry Research Instrumentation and Facilities: Multi-user (CRIF:MU) program, Professor Anne Kelley and colleagues Erik Menke and Tao Ye from the University of California - Merced will acquire an atomic force microscope (AFM). The award will enhance research training and education at all levels, especially in areas of study such as (a) structure and local conductivity of polymer thin films blended with nanoparticles, (b) charge transport through semiconductor nanoparticle aggregates, (c) amplification of surface induced chirality with enantioselective autocatalytic reactions, and (d) electrochemically driven nanoscale motors.
An atomic force microscope is used to characterize surface topography on a nanoscale level, distinguish different molecular coverage on surfaces, unfold polymers, calculate substrate stiffness, and quantify interaction forces. The AFM generally has a cantilever with a sharp point at its end used to scan the specimen surface. When the tip is brought into proximity of a sample surface, forces between the tip and the sample lead to a deflection of the cantilever. This deflection is often measured using a laser spot reflected from the top surface of the cantilever into a detector. This instrument will be used not only in research but also for research training of students and in outreach activities.
Intellectual merit: The instrumentation has allowed researchers at UC Merced to study chemical reactions as well as mechanical and electrical properties at the nanoscale. The instrumentation helped the Ye group to make advances at the forefront of AFM studies of biological molecules. They discovered novel gold microplate substrates for immobilization of biological molecules. Compared to traditional gold substrates, these substrates are inexpensive and have numerous superior properties,such as atomic scale flatness, and compatibility with sensitive optical techninques. The high resolution AFM was pivatol to the development of novel dynamic surfaces that can change interactions with biological molecules, which are important in fields ranging from biosensing to molecular machines. The Ye group used the dynamic surfaces to enable a breakthrough in the imaging of DNA on biofunctional surfaces, which yielded new insight into hybridization on DNA sensors and microarrays. The AFM has allowed the Menke group to charecterize their conductive polymer nanowire structures. Other groups at UC Merced are using the AFM to probe the local mechanical properties. The results have been appeared in four peer-reviewed publications in respected journals in chemistry and nanoscience. Broader impacts: The knowledge gained from the AFM-enabled research projects may lead to cheaper and more reliable biosensing technologies. The instrumentation has made possible numerous education and outreach activities. A total of twenty three users have been trained on the AFM technique. The AFM instrumentation has made possible several research projects for the graduate students. Three of our recent graduates used AFM as a key technique in their thesis/dissertation research. The instrumentation has provided research opportunities to six undergraduate students. Three low-income high school students from the ACS SEED project had hands-on experiences with AFM.
