| In recent years,electrochemiluminescence biosensor technology has attracted more and more attention in the field of food and biological detection.Compared with traditional methods,electrochemiluminescence biosensor technology has the characteristics of high sensitivity,low operation threshold,strong spatial-temporal controllability,wide range of linear detection and so on.However,electrochemiluminescence technology also has the problems of low efficiency of signal labels and easy to be affected by the surrounding environment,so it is urgent to establish an efficient and highly sensitive detection method.In view of the shortcomings of traditional electrochemiluminescence sensors,DNA nanotechnology was introduced into electrochemiluminescence sensors,which greatly improved the detection performance,especially the sensitivity and anti-interference ability.In this paper,DNA nanotechnology and functionalized nanomaterials are combined with electrochemiluminescence sensing technology,and two different electrochemiluminescence sensors are constructed from the perspective of reducing detection limit and improving anti-interference ability,which have been applied in food and biological disease detection.The research content of this paper is divided into two parts,which are summarized as follows:1.Mesoporous luminescent materials based on DNA isothermal amplification technology were used to detect the oligonucleotides of rabies virus.Rabies virus oligonucleotides are mainly found in biological tissues?such as saliva?,but their content is low.Therefore,we propose an electrochemiluminescence immunosensor based on DNA amplification technology for ultra-sensitive detection of rabies oligonucleotides.First of all,we synthesized mesoporous silica nanoparticles,and will be a lot of Ru?bpy?32+packaging and use the ssDNA silicon in silicon ball ball hole closed,then uses the DNA isothermal amplification techniques,in the presence of the target,can be a lot of amplification and ssDNA complementary Product DNA sequence,the sequence can open silicon ball hole,so it can release a large number of Ru?bpy?32+,so as to achieve the goal of signal amplification.The method has good performance in analyzing the nucleotides and saliva samples of rabies virus.The detection range of the former is 1.0×10-14 mol/L1.0×10-8 mol/L,and the detection limit is 1.885×10-1414 mol/L?S/N=3?.This method is much better than ELISA and fluorescence detection.2.A ratio electrochemiluminescence sensor based on aptamer was constructed for the detection of AFB1 in food.Aflatoxin B1?AFB1?is one of the most toxic chemical carcinogens.It is still a challenge to develop a simple,accurate and sensitive analytical method for detecting AFB1 in food.In this paper,a ratio adaptor sensor for accurate and sensitive detection of AFB1 is designed and verified on the basis of double signal strategy.Electrochemical methods were first used as models to verify the specific interaction between AFB1 and aptamer,in which ferrocene?Fc?-modified DNA sequence and methylene blue?MB?-modified DNA sequence were used as double signals.Therefore,the specific interaction between AFB1 and its aptamer is verified by Fc's"signal on"mode and MB's"signal off"mode.Due to its simple dual-signal mode,the electrochemical sensor is further extended to the construction of electrochemical luminescence adaptor sensor?ECL aptassensor?.In ECL system,double ECL signals are generated by CdTe/CdS/ZnS quantum dots?QDs?and luminol.Horhoradish peroxidase-modified gold nanorods?HRP/Au NRs?were used as quenchers/enhancers to quench the ECL signal of QDs by ECL energy transfer and catalyze H2O2 to enhance the ECL of luminol.Due to the use of internal self-calibration,the two ratios of aptasensors showed accurate and sensitive analytical performance for AFB1.The linear range was 5.0×10-12 mol/L1.0×10-9 mol/L,and the detection limit was 4.3×10-13 mol/L and 1.2×10-10 mol/L?S/N=3?. |
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