Studies On Nucleic Acid Biosensor And Logic Gates Based On Pseudomonas Aeruginosa

At present, many researchers pay attention to the contamination problem by Pseudomonas aeruginosa. Pseudomonas aeruginosa is detected using traditional medium method which is costing and time-consuming. So, it’s necessary to develop a more saving and efficient detection method.This study describes a simple and sensitive approach for visual and point-of-care detection of P. aeruginosa and its toxin genes based on multiple loop-mediated isothermal amplification (mLAMP) and lateral flow nucleic acid biosensor (LFNAB). After systematic optimization of LFNAB preparation and detecting conditions, the current approach was capable of detecting concentrations as low as 20 CFU/mL P. aeruginosa or its toxin genes within 50 min without complicated instrument, which is more sensitive than PCR. Therefore, this approach provides a simple, pollution free, sensitive, and low-cost point-of-care test for the detection of P. aeruginosa and its toxin genes. Then, the logic gates were simply applied to this biosensor. The main results obtained were summarized in the following portions.1. A approach for detection of P. aeruginosa and its toxin genes based on loop-mediated isothermal amplification (LAMP) was established. Universal primers of the internal standard gene ecfX and toxin genes (ExoS and ExoU) in P. aeruginosa were designed and he result showed that LAMP method could be applied to detection of P. aeruginosa.2. A simple and sensitive approach for visual and point-of-care detection of P. aeruginosa and its toxin genes based on multiple loop-mediated isothermal amplification (mLAMP) and lateral flow nucleic acid biosensor (LFNAB) were established. After systematic optimization of LFNAB preparation and detecting conditions, the current approach is more sensitive. Therefore, this approach provides a point-of-care test for the detection of P. aeruginosa and its toxin genes.3. The nucleic acid biosensing were combined with a logic gate. The logic gates were based on the multiple loop-mediated isothermal amplification (mLAMP) and lateral flow nucleic acid biosensor (LFNAB) to analyse the internal standard gene ecfX and toxin genes (ExoS and ExoU) in P. aeruginosa. The DNA of ecfX (ExoS and ExoU) as inputs that activate logic gates, the accumulation of Au-NPs produced a characteristic red band, as readout signals for logic gate operations. The logic gates of YES, AND, OR, INHIBIT and NOR were established.