| Photosynthesis is the very basic process in nature by which almost all plants convert solar energy into chemical energy. The process takes place in chloroplasts, the cellular powerhouses that are also responsible for the green color in leaves and algae. In the presence of visible light, carbon dioxide and water are transformed into glucose and oxygen during a complex series of chemical reactions. In nut shell, water is split into oxygen, protons and electrons. Sunlight penetrates the chloroplast and zaps the electrons to a high energy level, and a protein promptly grabs them. The electrons are passed down a series of proteins, which successively capture more and more of the electrons' energy to synthesize sugars until all the electrons' energy is spent. | |
| Since ages, Human being have been extracting this energy for its own benefit through several means. The most common, simple, old but dirty way is by simply burning fossil fuels such as coal, natural gas and oil. | |
| An intriguing novel approach has now been demonstrated by researchers at Stanford and Yonsei Universities. They have inserted ultrasharp gold nanoelectrodes (custom-made, AFM- compatible, nanoscale electrochemical probes that were shaped in the form of a flat, sharp needle with an aspect ratio of 10 and tip diameter of less than 30 nm) into living algae cells and extracted electrons, thereby harnessing an – albeit very tiny – electrical current. This is electricity production that doesn't release carbon into the atmosphere. The only byproducts of photosynthesis are protons and oxygen. | |
| The ultrasharp nanoprobes associated with the system allowed for penetration of the cell or chloroplast membranes using relatively low force and without disrupting the integrity of the cell (the cell membrane seals around the hydrophobic insulating material of the electrode). The team, led by Fritz B. Prinz demonstrates the aerobic extraction of photosynthetic high-energy electrons, both with and without mediators, from the single-celled alga Chlamydomonas reinhardtii.This approach potentially reduces energy losses associated with the multistep transformation of solar energy into products used for the production of biodiesel and bioelectricity. In addition, the system allows direct monitoring of specific charge transfer reactions in live cells, leading to broad applications for investigating developmental processes and the responses of cells and organelles to light and chemical stimuli. Reference: Nano Lett., 2010, 10 (4), 1137–1143 Authors: WonHyoung Ryu, Seoung-Jai Bai, Joong Sun Park, Zubin Huang, Jeffrey Moseley, Tibor Fabian, Rainer J. Fasching, Arthur R. Grossman and Fritz B. Prinz. |
