(577b) The Three-Pronged Approach to Investigate the Performance of Various Enzyme Immobilization Techniques

We will explore various enzyme immobilization techniques with different nanomaterial supports to study which mechanism shows the most potential for further use, what the shortcomings of each method are, and to suggest and best ways in which these methods might be improved upon. To achieve this goal, we will apply “the three-pronged approach.” This approach has the advantage of providing us with information about the performance of the complexes, morphology of the complexes, and where the bottlenecks lie for each of the complexes tested. For example, the potentiometric experiments performed in an electrochemical cell will provide information about the onset potential of the complexes (the potential at which current first is able to be generated), the activity of the complexes (how much current they can produce as a function of applied potential), and about the stability of the complexes (current output as a function of time at a fixed potential). Confocal or TEM imaging of the tagged enzymes incorporated into the complexes will provide us with information on the quantity of enzymes immobilized, the structure and morphology of the immobilized enzymes, and the porosity of the complexes. Finally, impedance analysis performed in an electrochemical cell will indicate what the major resistances to efficient power output arise from. For example, impedance analysis can be used to compare fuel mass transfer resistance, mediator mass transfer resistances, enzyme kinetics, and electron transfer resistances, allowing their relative magnitudes to be weighed thus pinpointing the bottlenecks of each complex. Once the relative advantages of various immobilization methods and electron transfer mechanisms are known, we can proceed toward developing further improved enzymatic electrode materials