ABSTRACT

For centuries, plants have utilized dynamic mechanisms of self-repair to develop fault-tolerant energy conversion schemes essential for withstanding climatic variability and ·uctuation of solar ·ux [1-5]. These mechanisms ensure the continual regeneration of plants responsible for enhanced photoef˜ciency and the inde˜nite prolongation of plant lifetime. On the other hand, most synthetic light conversion devices to date have remained largely static, lacking robustness in fault tolerance, photostability [6], material abundance [7], photoef˜ciency [8-10], and cost

7.1 Introduction .................................................................................................. 141 7.2 Background ................................................................................................... 142

7.2.1 Chloroplast Structure and Function .................................................. 142 7.2.2 D1 Protein Self-Repair Cycle ........................................................... 144

7.3 Biomimetic Regeneration of a Photoelectrochemical Complex ................... 145 7.3.1 Puri˜cation of the Assembled Complex ........................................... 147 7.3.2 SWCNT Fluorescence Measurements .............................................. 147 7.3.3 Photoelectrochemical Measurements ............................................... 149

7.4 Kinetic Model for the Self-Assembly of Photoactive Complexes ................ 151 7.4.1 Stage 1: Equilibration prior to Dialysis ............................................ 152 7.4.2 Stage 2: Dialysis above the CMC ..................................................... 154 7.4.3 Stage 3: Dialysis below the CMC ..................................................... 155 7.4.4 Determination of Kinetic Rate Constants and Stoichiometric

Coef˜cients ....................................................................................... 156 7.4.5 Results: Complex Formation throughout Dialysis ............................ 157

7.5 Conclusions ................................................................................................... 159 References .............................................................................................................. 159

effectiveness [11,12]. Recent efforts have focused on the incorporation of biomimetic mechanisms into synthetic photovoltaic devices. These studies often rely on the direct implementation of naturally derived photosynthetic complexes into synthetic photoelectrochemical cells, relying on synthesis procedures on tethering of the extracted proteins to various substrates [13-20]. In a recent study [21], scientists have expanded into using photosynthetic, extracted protein to synthesize the ˜rst photoelectrochemical cell capable of mimicking key aspects of the self-repair cycle used in the chloroplasts of plants. The remainder of this chapter focuses on chloroplast structure, function, and self-repair mechanisms, followed by a thorough discussion on its application to synthetic devices and the kinetic and thermodynamics quanti˜- cation of the self-assembly process integral to the self-repair process.