Fluorescent Probes Based On Pyrenyl Excimers Induced By Polyelectrolytes: Preparation And Application

Recently,fluorescent probes have attracted considerable attentions in chemical,biological and medical fields,owing to their operational simplicity,high sensitivity,real-time detection,low-cost and nondestructive test.Pyrene and its derivatives have been one type of particularly useful materials for the applications and designs of fluorescent probes,because of their chemical stability,easy syntheses,high quantum yield,long fluorescence lifetime,especially,the formation of excimers of pyrene moieties under certain conditions.Nowadays,multitudinous fluorescent probes based on pyrene and its derivatives have been developed and applied for the detection of various biomolecules and metal ions,and so on.Many of them have possessed excellent sensitivity and selectivity,however,restricted by complicated synthesize or poor water-solubility,they still could not be wildly used for the practical application.Therefore,it seems important significance to develop pyrenyl fluorescent probes possessing many advantages,including easy synthesis,excellent water-solubility,real-time detection and practical application.Based on the above design principal and purpose,the following work were complicated in this paper:1.A pyrene-based probe sodium 4-(pyren-1-yl)butane-1-sulfonate(PBSS)was synthesized.In different buffer solution,induced by the polyelectrolyte poly((diallyldimethylammonium chloride)(PDDA),PBSS/PDDA excimers(PPE)were obtained with the studies of its spectral analysises.2.PPE were utilized for the detection of environment pollutant 2,4,6-trinitrophenol(TNP).TNP is widely used in dye industries,pharmaceutical and firework fields,besides,it also is one of typical environment pollutants,therefore,many attentions have been payed to the studies and detection of TNP.In this paper,we have developed a novel approach for rapid detection of TNP based on the quenching of PPE fluorescence by TNP.Based on a series of tests conducted to explore the mechanism,we confirmed that TNP bound with PPE by electrostatic,π-π stacking and charge-transfer inteactions with the dissociation of PPE.Based on the unique mechanism,we realized the visual detection of TNP with high sensitivity and high selectivity with the limit of detection(LOD)as low as 5 n M.PPE could be practically useful in the rapid detection of TNP with high sensitivity and the LOD for TNP in soil and tap water was calculated to be 10 n M and 22.9 ppb,respectively.3.PPE were applied for the detection of the biomolecule heparin.As an anticoagulant,heparin plays an important role in the regulation of various normal physiological and pathological processes including cell growth and differentiation.Thus,close monitoring and quantification of heparin in serum is still of important significance for regulation of the physiological process and for clinical applications.Based on the monomer-excimer conversion of pyrene induced by heparin leading the dissociation of PPE,we realized the rapid and visual detection for heparin with the low LOD as 0.14 μM.During the visual detection of heparin,the LOD was obtained as 2.0 μM under UV light.In addition,in bovine serum albumin,PPE still possessed desirable results for the detection of heparin.