Genotoxicity monitoring using a 2D-spectroscopic GFP whole cell biosensing system

A 2D-spectroscopic genotoxicity biosensing system is presented. This optical sensing system monitors the genotoxicant-induced expression of green fluorescent protein (GFP) in a recombinant Escherichia coli strain. In this organism, GFP synthesis is driven by the recA gene promoter of the bacterial SOS DNA repair system. Using nalidixic acid as a model genotoxicant, we have demonstrated a response range that varies as a function of the excitation wavelength. When GFP fluorescence was monitored at 510 nm, the linear working range to nalidixic acid was within the range of 0.03-0.3 ppm at 390 nm excitation and 0.05-0.3 ppm at 480 nm excitation.