Using IDF electrochemical technology it has been proved possible to detect EtBr from an microbiology lab surface with a sensibility lower than the strict 12 nM concentration as required by the European law , the LoD of 12 nM represent also at the moment an important milestone to the use of EtBr as electrochemical probe for PCR-free procedures that usually operate between 10 -9 and 10 -8 nM of nucleic acids.