| Electrochemiluminescence(ECL),as a fresh analytical technique,integrated the controllability of electrochemical potential and high sensitivity of ECL,also has a low background signal,easy to operate,no external light source and many other advantages,it is widely used in analysis and detection.To the best of our knowledge,molecular imprinting technique(MIT)is vividly described as "artificial locks" that identify "molecular keys",which give full play to the advantages of specific recognition of the target molecule.Therefore,the application of molecular imprinting technology to ECL sensing is bound to reinforce the selectivity and sensitivity of ECL sensors.In this paper,two molecularly imprinted ECL sensors have been designed to achieve highly sensitive detection of a-ergocryptine and propranolol.(1)Preparation of Solid-state MIP/CdTe-Ru@SiO2/GCE ECL sensor and Its Analytical ApplicationOne-pot synthesis of semiconductor materials CdTe quantum dots(CdTe QDs)was used in this experiment.ThG ECL emission spectrum of Ru(bpy)32+ sufficiently overlapped with the absorption bands of CdTe QDs,therefore,resonance energy transfer between Ru(bpy)32+ and CdTe QDs can occur.Ru(bpy)32+ was the donor transfers energy to the acceptor(CdTe QDs),thereby greatly enhancing the ECL signal.Based on this,the negatively charged CdTe QDs are combined with positively charged Ru(bpy)32+ via electrostatic adsorption.CdTe-Ru@SiO2 nanoparticles(NPs)were synthesized using a water-in-oil microemulsion method.This nano-composite structure shortens the distance of energy transfer between the donor and the acceptor,further improves energy transfer efficiency.Using this composite nanoparticle as an electrochemiluminescence probe and combining the high selectivity of the molecularly imprinted polymer,a MIP/CdTe-Ru@SiO2/GCE solid-stated electrochemiluminescence sensor was prepared.Under optimal experimental conditions,the concentration of a-ergocryptine showed a good linear relationship withinthe range of 1 fg/mL?0.3 ?g/ML,the limit of detection is 0.18 fg/ml(S/N=3).The sensor can be used for the detection of a-ergocryptine in actual starch samples.The recovery rate was 94.7%-107.8%.The method has good selectivity,high detection sensitivity and good reproducibility,and provides theoretical guidance and support for the rapid and high-efficiency detection of a-ergocryptin in food and processing materials.(2)Preparation of Solid-state MIP/RuSi-PEI/GCE ECL sensor and Its Analytical ApplicationOn the basis of the previous experiment,this experiment chose a non-polluting and non-toxic linear polyethylenimine(PEI)instead of tripropylamine as a co-reactant.RuSi NPs were synthesized by sol-gel method.For the reason that the surface of RuSi NPs is negatively charged and the amino-rich PEI is positively charged,RuSi NPs and PEI are combined into RuSi-PEI nanospheres through electrostatic adsorption.Then,the nanospheres are modified on the surface of the electrode,and after they are naturally dried,molecularly imprinted polymer membrane containing the target molecule propranolol was modified to form a MIP/RuSi-PEI/GCE ECLsensor.There is a good linear relationship between the ?IECL(the difference before and after cultivate in propranolol)and the propranolol concentration.The detection range is 1.0×10-11?5.0×10-9M and the detection limit is 0.54 pM(S/N=3).The sensor can also be used for the determination of propranolol in serum.The recovery rate is 93.8%?112.7%.It has a potential value of detection of drug analysis. |
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