A novel design of a photosynthetic microbial fuel cell (PMFC) is constructed. It is a membrane-less and mediator-free apparatus with a gilding gold mesh as an anode and a graphite carbon cloth as a cathode. The electrode spacing is 4 cm. Spirulina platensis is aggregated and deposited on the anode to form a thin biofilm. Results show that the chlorophyll (Chl) content of the biofilm attributed the PMFC's electricity performance. The open circuit voltage (OCV) reading of PMFC is proportional to Chl content when the Chl was below 0.5 mg. The maximal OCV of PMFC is 0.49 V. When the PMFC was connected to an external resistance of 1 k Omega, a maximum power density of 10 mW m(-2) was obtained. This designed PMFC yielded competitively high OCV and power density as compared to other microbial fuel cells reported in the literature. (C) 2012 Elsevier Ltd. All rights reserved.