Longwood University 1 article published in JoVE Chemistry Preparation and Application of a New Bacterial Biosensor for the Presumptive Detection of Gunshot Residue Amorette E. Barber1, Harley Hodges2, Sarah E. G. Porter2, Elle Richardson1, Katelyn Rowland2, Andrea Soles1 1Department of Biological and Environmental Sciences, Longwood University, 2Department of Chemistry and Physics, Longwood University A protocol is presented using synthetic biology techniques to synthesize a set of bacterial biosensors for the analysis of gunshot residue, and to test the functioning of the devices for their intended use using fluorescence spectroscopy.