Biofilm monitoring through the detection of cyclic diguanosine-monophosphate with an easy-to-use electrochemical sensor

The identification and monitoring of biofilm is of utmost importance because it ensures the survival of bacteria in a variety of environments, such as nature, medical indwelling devices, hospital surfaces, or the food industry. Here, we describe the novel application of a screen-printed electrode modified with nanomaterials for the in situ detection of bacterial biofilm. This approach enables simple, rapid, and highly sensitive and selective electrochemical detection of cyclic diguanosine-monophosphate (cdGMP). The best electrochemical signal of cdGMP was obtained after testing several electrode materials and screen-printed electrodes modified with different nanomaterials, different electrolyte solutions, pH, and electrochemical technique parameters. Using the anodic peak of the cdGMP on screen-printed electrodes modified with carbon nanotubes (CNT-SPE), the sensor showed excellent sensitivity, with a 25 nM–1 µM linear range, and a limit of detection of 15 nM. The sensor allowed the selective detection of cdGMP, with low interference from other molecules and was successfully applied to real sample analyses (laboratory biofilm produced by various bacterial species over distinct time intervals).