PH-responsive color-changing nano-particles based on bacitracin and thymolphthalein and application thereof

Abstract

The invention discloses a preparation method of pH-responsive color-changing nano-particles based on bacitracin and thymolphthalein co-assembly and a method for visually detecting escherichia coli by using the nano-particles. During preparation, the bacitracin and the thymolphthalein are co-assembled, and the thymolphthalein and the bacitracin are co-assembled by utilizing the polarity change of a solution to form nanoparticles; the method comprises the following steps: firstly, preparing an aptamer modified magnetic bead, then constructing a sandwich structure by using nanoparticles, the aptamer modified magnetic bead and bacteria, finally, stimulating thymolphthalein to develop color by adding a NaOH solution, and constructing a linear relationship with E.coli concentration change by detecting a delta OD value through a microplate reader or detecting an (R + G) / B value through a smart phone, so as to realize quantitative visual detection of E.coli. Experiments such as structural characterization, experimental condition optimization and sensing performance analysis on the AMP / TP NPs material prove that the material can be used for E.coli analysis and detection. The detection method disclosed by the invention is convenient to operate, high in response speed and easy to popularize and use.

Description

technical field [0001] The present invention relates to nanomaterials and their applications, specifically a pH-responsive color-changing nanoparticle (Nanoparticles, NPs) based on bacitracin (an apparent light yellow antimicrobial peptide, AMP) and thymolphthalein (TP) and Its preparation method and application. Background technique [0002] Escherichia coli ( Escherichia coli , E. coli ), also known as Escherichia coli, is an opportunistic zoonotic pathogen that poses serious hazards to human and animal health. Due to pathogenicity E. coli The resulting infection of animals and contamination of animal products is a serious problem in terms of animal health and public health safety. E. coli The serotypes can cause gastrointestinal infections in humans or animals, mainly caused by specific pili antigens, pathogenic toxins, etc. In addition to gastrointestinal infections, they can also cause urinary tract infections, arthritis, meningitis and septicemia infection etc....

AI Technical Summary

Problems solved by technology

However, the material synthesis of this method is cumbersome and the detection method is relatively complicated.

Moreover, the labeling process can easily lead to the inactivation of antibodies or enzymes, resulting in false negative signals, the required detection drugs are expensive and the invention needs to be carried out in a sterile environment, which requires high detection environment

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