Detection Of Illegal Drugs By The Aie Luminogens

Nowadays,illegal drug crime has become one of the global public security issues,which is gradually undermining the stability of the whole society.Therefore,most of countries have tried to crack down on drug crimes though stringent legislation,but with limited success.Among them,the detection methods of gathering evidence conviction was far dragged behind,and have become the main problem of restricting rapid crackdown on drug traffickers.At present,although many large-scale instrumental analysis tests are widely used and can accurately detect illicit drugs,but their shortcoming are becoming more and more obvious.Hence,developing rapid and sensitive detection of illegal drugs seized on the spot has become the focus of research in this field.As a hot research in the detection field,fluorescent probes acquired remarkable achievement in various detection aspects.Meanwhile,the fluorescent sensors based on aggregation-induced emission(AIE)luminogens have been widely applied in diverse sensing areas,and shown distinct advantages.The concept of aggregation-induced emission(AIE)was coined and introduced in detail by Tang et al.in 2001,which was exactly opposite to the aggregation-caused quenching(ACQ)effect and refers to a unique phenomenon that a kind of non-or weakly emissive luminogens in dilute solutions are induced to emit intensely upon aggregation or in the solid state.Excellent optical stabilitiest and high solid-state fluorescence quantum yields make the become a hot research topic in chemosensor.In this thesis,we devote to development of new illegal drug detection methods and varieties of novel illegal drugs fluorescence sensing systems based on the AIE luminogens(AIEgens)are constructed.First,we combine the AIEgen of TPPE with the supramolecular cucurbit[7]uril(CB[7])and design a novel chemosensor for rapid and sensitive detection of methamphetamine(METH)in methanol solution.After simple mixing,the self-assembed AIE-active CB[7]?TPPE was obtained,which exhibited good water solubility and weak emission in aqueous.Based on the competitive binging affinity,CB[7]?TPPE was selected as a chemosensor to detect METH,with a limit of detection as low as 0.43 ?mol/L.Moreover,this probe exhibited excellent response toward METH at high concentration,the change in fluorescence intensity and colour(yellow instead of green)could be directly observed.We also fabricated portable test strips for METH rapid,visibly dection,of which the LOD could reach 10 ?mol/L in methanol.Second,a METH sensor with high sensitivity and selectivity is prepared by the interaction between the AIEgen of TPM and CB[7].When added CB[7] into the solution of TPM,the fluorescence intensity of TPM increase linearly.In a certain concentration of CB[7] solution added METH,which will occupy the cavity of CB[7] and form a complex CB[7]?METH.Then,added TPM,it can not interfere with CB[7]?METH because the binding constant is less than METH.However,when added METH less than CB[7] in the solution,there will be CB[7] remaining,so TPM can complexate with unsettled CB[7],which leads to a decrease in fluorescence compared to without METH.We also considering the practical application of the sensor and verified that the sensor can high sensitivity detection of METH in both water and synthetic urine,and obtained the LOD is 31.3 and 93.8 nmol/L,respectively.This simple fluorescent sensor shows unprecedented sensitivity to METH and provides a new method for rapid detection of METH.Third,we using the AIEgen of TPE-phos and ELISA,successfully design and prepare a novel method for detection of METH.After adding METH to the sensor,the platform can be constructed by specific binding between antigen and antibody,and the alkaline phosphatase is attached at the end of the sensor.Therefore,after addition of TPE-phos,the phosphate group on TPE-phos is cut off by alkaline phosphatase,and generate AIEgen with poor water solubility,resulting enhanced emission of the solution.Therefore,the change of fluorescence intensity with METH can be used to realize the quantitative detection of METH,the LOD is as low as 2.97 nmol/L.This work provides an effective method for the rapid identification of METH.Finally,we successfully developed a new method for cocaine detection based on AIEgen of TPE-TTA binding to cocaine aptamer and using exonuclease I as an assistant.After a series of experimental optimization,the optimal detection conditions for this sensor are obtained,and the response to cocaine under this condition is tested.Based on the changed of emission,this simple sensor showed high sensitivity and selectivity to cocaine,both in a buffer solution or in actual urine,the LOD is calculated to be 0.66 and 1.0 ?mol/L,respectively,and other illegal drugs can not interfere the detection.This sensor device is simple and easy to operate,and has the potential of realizing the miniaturization of cocaine detection.