Biotin has been successfully incorporated into polylactic acid (PLA) nanofibers through electrospinning to prepare membrane substrates for biosensors based on biotin-streptavidin specific binding. Biotin incorporated PLA nanofiber membranes were characterized with scanning electron microscopy (SEM), electron probe microanalysis (EPMA), and confocal microscopy. Under optimized conditions, small fiber size and uniform morphology were achieved for PLA nanofibers with and without biotin incorporation. Sulfur mapping indicated a non-uniform distribution of biotin on the membranes, presumably due to aggregation of biotin during the electrospinning process. Pre-blocking the membranes effectively eliminated non-specific bindin g between streptavidin and PLA. Preliminary biosensor assays confirmed that streptavidin immobilized on the membrane surface could capture a biotinylated DNA probe. (c) 2005 Elsevier B.V. All rights reserved.