Biosensor, procedure for obtaining said biosensor, method for the detection of Pseudomonas aeruginosa, and detection kit using said sensor for the rapid detection of P. aeruginosa

Pseudomonas aeruginosa is a gram-negative opportunistic pathogen that is particularly problematic in Intensive Care Units and ranks among the most significant causes of hospital-associated bacterial infections. Its broad and potent pathogenic profile, along with its ability to exhibit multidrug resistance, enables it to cause acute infections that often become chronic, making it associated with high morbidity and mortality in many groups of immunocompromised patients. Due to its ease of transmission, the large number of multidrug-resistant strains, and the long and complex diagnostic times, a new system has been developed to detect Pseudomonas aeruginosa in clinical patient samples in less than 30 minutes. The presented invention enables the semi-quantitative detection of Pseudomonas aeruginosa DNA through the implementation of molecular gates on hybrid porous organic-inorganic supports that specifically and selectively recognize bacterial DNA. In this system, the designed oligonucleotides acting as molecular gates, which block the pores of the support, are capable of detaching from the surface only in the presence of the analyte, thereby enabling the release of a fluorogenic indicator previously introduced into the porous interior. Monitoring the signal resulting from the release of the fluorogenic indicator by the developed biosensor has demonstrated its ability to distinguish, in less than 30 minutes, between clinical samples from healthy patients and those infected with Pseudomonas aeruginosa, with a low detection limit between 9.8 × 10⁻² and 10 CFU mL⁻¹ and high specificity against other species of the Pseudomonas genus. This new system allows for the detection of bacterial DNA even at the early stages of infection, thereby helping physicians avoid resorting to empirical treatments that contribute to the development of antimicrobial resistance.