Dissertations and Theses

Date of Award


Document Type



Chemical Engineering

First Advisor

Charles Maldarelli


Self-propelled colloids, Enzyme, Elastase, Active colloids, Microspheres


Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose biomolecules for self-propulsion. We select elastase as a catalyst and coat it on the surface of polystyrene (PS) particles, and use SucAla3-pNA as a substrate to examine the activity of the elastase-coated particles. We exploit biotin-streptavidin chemistry to couple the elastase on the surface of the PS particles. We confirm that SucAla3-pNA can be effectively decomposed by elastase and elastase-coated particles using spectrophotometric measurement. The results demonstrate that the elastase-coated PS particles are catalytically active, showing great potential to be used in biologically-friendly system.



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