Multiplex Detection Of Bacteria And Cancer Cell Imaging And Killing Based On Conjugated Polymer Nanoparticles

Resonance energy transfer is an important tool for biochemical analysis and detection,which can realize wavelength regulation by simple design.Conjugated polymer nanoparticles(CPNs)can encapsulate a variety of hydrophobic materials,meet the requirements of resonance energy transfer on the distance between the donor and the acceptor,and have the advantages of good biocompatibility,high fluorescence,easy preparation and easy modification.In this paper,two works have been carried out based on the resonance energy transfer of CPNs.The specific contents are as follows:1.Multiple detection of bacteria based on CPNs.Water,food,and medicines are very susceptible to bacterial contamination during production,transportation,and sales.In clinical practice,infections and diseases caused by bacteria are very common.The development of rapid and sensitive detection methods,especially multiple detection,is of great significance for early detection,elimination from the source,and early treatment to block the rapid development of the disease.We synthesized two types of CPNs.One contained conjugated polymer PEPV(PENP),and the other contained PEPV and BFTB(PEBFNP).The fluorescence resonance energy transfer between PEPV and BFTB resulted in the red shift of emission wavelength.Nanoparticle PENP modified with antibiotic polymyxin B(PMB),named PENP-PMB,specifically recognized Gram-negative bacteria,and PEBFNP modified with vancomycin(Van),named PEBFNP-Van,specifically recognized Gram-positive bacteria.When the two modified nanoparticles were added into the detection system and excited at the same wavelength,two different emission peaks could be generated,and the fluorescence intensity was quantitative to the concentration of bacteria.Therefore,a rapid,quantitative and multiple detection method for Gram-negative and Gram-positive bacteria was established.antibiotics which can identify bacterial directly was low cost and relatively stable.The whole detection process from the interaction with bacteria to the fluorescence detection process only need less than 1 h,of which the time was short and the method was simple.Using two nanoparticles which can emit different wavelengths at the same excitation wavelength,this assay achieves rapid simultaneous detection of bacteria,saving cost and time,and providing a new method for the detection of bacteria in the environment,food,and clinics.2.On the basis of the above CPNs,the recognition and imaging of tumor cells were carried out,and chemiluminescence was introduced to establish photodynamic therapy independent of external light source.Photodynamic therapy is a new type of minimally invasive technology,which has a good development prospect in the treatment of tumors.However,due to the absorption and scattering of light by biological tissues,the light penetration ability is limited,which makes the treatment of deep tumor by photodynamic therapy difficult.Conjugated polymer nanoparticles(He PEBFNP)were prepared by using amphiphilic DSPE-PEG-Folate and PSMA to coat hemin,PEPV and BFTB by nano-reprecipitation method.Folate on the surface of He PEBFNP can target tumor cells for recognition and imaging.After adding a chemiluminescence substrate,PEPV was excited by chemiluminescence energy transfer,and then BFTB was excited by fluorescence resonance energy transfer.BFTB could generate reactive oxygen species to kill tumor cells.Nanoparticles with multiple functions of targeting,imaging,providing chemiluminescence catalysts and photosensitizers are synthesized in one step.Using chemiluminescence instead of external light sources,the method provides a new strategy for photodynamic therapy applied to the treatment of deep tumors.