T.J. Mountziaris earned a Diploma in Chemical Engineering with highest honors from the Aristotle University of Thessaloniki, Greece, and a Ph.D. in Chemical Engineering from Princeton University. After completing postdoctoral studies at the University of Minnesota, he started his academic career at the State University of New York (SUNY) at Buffalo. From 2003 to 2005 he served as Program Director for Particulate and Multiphase Processes at the National Science Foundation and subsequently joined the University of Massachusetts as Professor and Head of Chemical Engineering, a position that he held until 2014. He is currently the Program Director for Process Systems, Reaction Engineering, and Molecular Thermodynamics at the National Science Foundation and a Professor of Chemical Engineering at the University of Massachusetts. He is the recipient of numerous honors and awards, including the Norman Hackerman Award of the Electrochemical Society, The Chancellor’s Award for Excellence in Teaching of the SUNY system, a Guest Professorship in Process Engineering from ETH-Zürich, and a visiting Professorship from Princeton University. Two of his U.S. Patents on template-assisted synthesis of semiconductor nanocrystals have been licensed by a startup company.
Nanocrystals of II-VI compound semiconductors, such as CdSe and ZnSe, and core-shell structures based on them have unique properties, including size-tunable photoluminescence, narrow emission spectrum, broad excitation, high brightness, high extinction coefficients, and excellent photochemical stability. These materials have a wide range of novel applications, including medical diagnostics, high color definition display technologies and solar energy conversion. ZnSe nanocrystals are particularly attractive, because they do not contain toxic heavy metal ions, such as Cd2+, and can be doped relatively easily with transition metal ions, such as Mn2+ and Cu2+, thus enabling further tuning of their optoelectronic properties. We have developed a technique for growing II-VI nanocrystals that employs microemulsions and liquid crystals as templates for controlling both size, shape and size distribution of the nanocrystals. Kinetic Monte Carlo simulations of the process revealed the underlying mechanisms of particle nucleation and growth while Density Functional Theory calculations provided insights on doping mechanisms and enabled tuning of the nanocrystal growth and doping techniques. Extraction of the nanocrystals from the templates, annealing, and coating of their surfaces with molecules containing specific functional units enabled their stabilization in aqueous solutions and conjugation with biomolecular probes for applications in medical diagnostics. A new class of optical biosensors based on ZnSe nanocrystals has been developed for rapid quantitative detection of molecular or biological targets in solution. The biosensors have high sensitivity and selectivity by utilizing changes in the fluorescence emission spectra of ZnSe nanocrystals induced by the binding of the probes to the target biomolecules. Detection of single-base DNA mutations and separation-free assays that enable rapid quantitative detection of proteins in solution will be discussed as examples. These biosensors are attractive for developing miniaturized lab-on-a-chip portable devices that could enable rapid multiplexed detection of several biological targets for medical, environmental, and food safety applications.