Nanoprobes Based On Chemiluminescence Resonance Energy Transfer Are Used For Imaging And Detecting Alkaline Phosphatase

Drug-induced liver injury(DILI)may cause liver failure and result in mortality and is thus a widespread concern in modern medicine.Notably,the high mortality ratio of DILI is due to untimely and inaccurate diagnosis.Therefore,developing real-time methods for the accurate in situ diagnosis of DILI is imperative.Alkaline phosphatase(ALP)is overexpressed in the sera of persons with DILI,and thereby regarded as a biomarker for DILI diagnosis.Alkaline phosphatase(ALP)is a zinc-containing glycoprotein that specifically hydrolyzes phosphate groups and catalyzes dephosphorylation of various substances in the body,such as nucleic acids,proteins and sugars.Moreover,ALP is overexpress in the sera of persons with DILI.So,it is expected to be used as a biomarker for the diagnosis of DILI.Compared with traditional photoluminescence detection methods,chemiluminescence(CL)method possesses the advantages of lower tissue photodamage and background interference because no external light is involved,has been a highly sensitive method for microanalysis and trace analysis in recent years.Especially in the chemiluminescence resonance energy transfer(CRET)system,the energy can be transferred from the energy donor to energy receptor through the resonance energy transfer,thus red-shifted the CL wavelength and enhanced the CL intensity,even prolonged CL time.Covered the shortages of CL method such as short wavelength,weak intensity and short time.Therefore,develop a new probes based on CRET to imaging ALP in vivo will help to promote the timely and accurate diagnosis of DILI.Here,we designed and synthesized nanoprobes based on silica and conjugated polymers for imaging ALP in vivo.The work carried out in this paper as follows :1.We designed a nanoprobe named MSN@RhB@?-CD@AMPPD based on chemiluminescence resonance energy transfer(CRET)for imaging alkaline phosphatase(ALP)in vivo.The probe is composed of three parts :3-[2-spiroadamatane]-4-methoxy-4-[3-phosphoryloxy]-phenyl-1,2-dioxetane)Dioxetane(AMPPD),a specific chemiluminescence substrate of alkaline phosphatase,was as energy donors,?-cyclodextrin(?-CD)was used as linker and Rhodamine(Rh B)dye loaded in mesoporous silica as energy receptor.Phosphates in substrate AMPPD can be hydrolyzed by alkaline phosphatase and emit chemiluminescence at470 nm,through CRET,the energy was transferred to RhB,RhB was excited and emit fluorescence at 580 nm.Hence,the nanoprobe realized the ultra-sensitive detection of ALP in vitro,the detection limit was 0.0748 U/L.More importantly,MSN@RhB@?-CD@AMPPD successfully accomplished in situ monitor ALP in mouse,indicating DILI.2.We applied conjugated polymer(PFDBT)to design a nanoprobe(PFDBT-CD-AMPPD)for detecting ALP based on chemiluminescence resonance energy transfer.The probe also consists of three parts,AMPPD as the energy donor,the conjugated polymers as energy receptor,at the same time,beta-cyclodextrin(?-CD)covalently linked to conjugated polymers as linker,The substrate AMPPD is intercalated in ?-CD through the host-guest interaction,which connects the energy donor and the energy receptor.When the phosphate group of AMPPD is hydrolyzed by alkaline phosphatase,it emits chemiluminescence at 470 nm,by means of CRET,the energy is transferred to conjugated polymer,which emits a fluorescence at 680 nm.In our design strategy,the distance between donor and receptor is shortened because of the covalent bond and the host-guest interaction between energy donor and energy receptor,enhanced the energy transfer efficiency.Moreover,due to the signal amplification of conjugated polymer,the nanoprobe can be realized the high sensitivity detection of ALP.Currently,the probe has been successfully used to monitor the level of ALP in vivo.