An anoporous anodica lumina( NAA)-based sensors ystem for the detection of Mycoplasma was developed through the implementation of "molecular gates" selectivet ot he presence of this bacterium. The capped support showed an egligible cargo release, while presence of Mycoplasma genomic DNA resulted in the release of rhodamine Bf luorescent dye. This sensor system presentsalimit of detection of 20 genomic DNA co-pies·mL À1 and was applied to the detection of Mycoplasma bacteria in competitive environments, such as culture cell media.Mycoplasma is as mall bacterium (diameter0 .2 mm) without cell wall, immunet oc ommon antibiotic, capable of passing through bacterial filters and of great importance because of its commonp resence in cell cultures in clinical, research and biopharmaceutical industry. [1] Besides, Mycoplasma is also related with the development of important pathologies such as pneumonia,r heumatoid arthritis, cancer andn on-gonococcal urogenital diseases, among others. [2][3][4][5][6] Historically,p olymerase chain reaction( PCR) methods and culture-based approaches have been used extensively for Mycoplasma detection. However,e ven thought hese methods are very sensitive, they have several drawbacks such as high cost, the need of trained personnel, and ar elativelyl ong time before results are obtained. [7] As an alternative, the design of new sensings ystemsf or Mycoplasma detection that overcome the cited drawbacks are of importance and have been recently