Synthesis Of Long-lived Organic Room Temperature Phosphorescence Materials And Detection Of Biomarkers

Room temperature phosphorescence(RTP),as a class of long-lived luminescence material due to its large Stokes shift with high signal to noise ratio,which in the field of biological imaging,chemical sensors,information security caused great concern.There are few reports on large-size long-lived room temperature phosphorescence crystals with green light excitation and realization of full-color long-lived RTP in water environments.Therefore,this work focuses on the development of green light excitation and full-color long-lived phosphorescence in water environments,and explores its luminescence mechanism and its application in biomarkers.The main research contents are as follows:(1)Long-lived RTP materials are promising to be applied in various fields including security information,medical diagnostics,and molecular imaging due to their unique optical properties.Previous RTP materials are mainly excited by ultraviolet light,while synthesizing long-lived RTP materials with visible-light-excitation remains a challenge.In particular,the long-lived RTP materials that can be excited by green light are still rare.Herein,a feasible and concise chemical strategy for constructing hydrogen bonds frameworks in aqueous environment is developed to fabricate large-size,green light excition,and excitationdependent long-lived RTP carbon dot crystals(m,p/CDs-ME).The RTP performance of the crystals exhibits strong excitation wavelength dependence,leading to a full range of visiblelight tuning from blue to red.Importantly,the maximum excitation wavelength of the RTP crystals is around 500 nm,thus successfully realizing green light excitation.The m,p/CDsME presents long-lived phosphorescence(130 ms)under 500 nm excitation in aqueous solution,making it highly suitable for dopamine detection.This work not only provides a general guideline for the development of large size long-lived RTP crystals,but also extends the operation scope of long-lived RTP materials in the detection of biomarkers by green light excitation.(2)Long-lived RTP materials have been widely utilized in the field of biological and chemical sensing,due to their unique characteristics of long-lived luminescence and no background fluorescence.However,the realization of full-color RTP in aqueous solution still remains a great challenge.Herein,a feasible strategy for achieving high stability and fullcolor RTP of CDs-based composite materials(m,p-CDs@CA,e,s-CDs@CA,n-CDs@CA,t,p-CDs@CA,p,p-CDs@CA)in aqueous environment was reported by constructing rigid hydrogen bonds network.The obtained m,p-CDs@CA composite materials exhibit deepblue RTP with phosphorescence quantum yield of 23.2% and lifetime of 1.74 s,and the afterglow can last for over 12 s.More importantly,the m,p-CDs@CA composite materials are desirable in detection of biomarkers,because of excellent stability,dispersion and longlived RTP properties.The m,p-CDs@CA suspension also displays excellent sensitivity,and the limitation of detection as low as 5.61 nM and 550 nM for biomarkers 5-hydroxyindole-3-acetic acid(HIAA)and Serotonin(5-hydroxytryptamine,HT),respectively.Meanwhile,the sensing performance exhibits excellent selectivity even in the presence of other competitive species in blood plasma and urine.With superior selectivity,the long-lived phosphorescence probe based on m,p-CDs@CA suspension could be as an effective biomarker for carcinoid identification,which has potential application in clinical analysis.