| Electrochemiluminescence（ECL）analysis method has received wide attention due to its high sensitivity,low background signal,fast response,and desirable controllability.Molecularly imprinted polymer（MIP）is a polymer synthesized with a target molecule as a template,with high recognition and good selectivity,and has shown great potential in various application fields.The molecularly imprinted electrochemiluminescence（MIECL）sensor prepared by combining MIP and ECL with the advantages of both could achieve highly sensitive and selective detection of target molecules.However,currently reported MIECL sensors suffer from problems such as cumbersome modification process,low reproducibility,time-consuming and high cost,which greatly limits the further development of MIECL sensors.Cobalt-based nanoarrays have become one of the promising electrode materials in recent years due to their excellent characteristics such as large specific surface area and good electrical conductivity.Therefore,in this paper,three MIECL sensors were constructed based on the cobalt-based nanoarray electrodes for the sensitive detection of bisphenol sulfur（BPS）,sulfadiazine（SDZ）,and spiramycin（SPI）.The constructed MIECL sensor shows good analytical performance and expands the application of cobalt-based nanoarrays in electrochemiluminescence sensors,which is of great significance.The specific research work of this paper is as follows:1.A substitute for bisphenol A（BPA）,BPS exerts endocrine disruptive and toxic effects and could pose potential risk on human health and environment safety.Herein,The MIECL sensor was fabricated based on cobalt nitride（Co N）nanoarray for the sensitive detection of BPS.Firstly,Co N nanoarray with outstanding electrical conductivity was prepared by hydrothermal method and ammonia nitridation reaction and it directly served as the sensor platform.Then,by means of the cation exchange effect of the Nafion membrane,the ECL probe of Ru（bpy）32+could be adsorbed on the porous Co N nanoarray electrode to obtain a boosted ECL signal.Afterwards,a MIP membrane was modified on the surface of the electrode,and the prepared MIECL sensor after removing the template molecule could realize the specific recognition of BPS.Based on the superior properties of the Co N nanoarray electrode,the linear relationship between constructed MIECL sensor and the logarithm of the BPS concentration within the range of 2.4×10-9 mol/L-5.0×10-5mol/L shows good performance and the correlation coefficient（R2）is 0.9965,the limit of detection（LOD）could reach 8.1×10-10mol/LL（S/N=3）.In addition,To verify the accuracy of the proposed method,the high performance liquid chromatography（HPLC）method was adopted to analyze drinking water samples as a comparison.The t-test result proved that discrepancies between HPLC method and the experimental method were acceptable.The developed MIECL sensor exhibits highly sensitive,selective,reproducible and stable analytical performance,which opens up a new pathway for the detection of BPS and other BPA substitutes in drinking water samples.2.In this work,an ratiometric MIECL sensor based on the ratio of electrochemiluminescence response and electrochemical signal was firstly proposed for for the determination of SDZ.At first,the porous Ni Co2O4nanoarray electrode with a large surface area and excellent conductivity could support a large amount of ECL probe graphite-like carbon nitride（g-C3N4）to obtain an enhanced ECL signal.Among them,the ECL signal from g-C3N4is selected as the working signal.After that,the MB-MIP solution was modified on the electrode,and the Methylene blue（MB）could produce a stable electrochemical signal was worked as the internal reference signal.With the elution and re-adsorption of the template molecule SDZ in the MIP,the ECL signal changes,while the internal reference signal from the MB remains relatively stable.The two signal probes respectively generate signals at different potentials to avoid cross-talking interferences.The developed sensor utilized the ratio response value(ECLg-C3N4/Current MB)as the output signal to correct the system and external interference to achieve accurate and sensitive determination of the SDZ,the detection limit（LOD）is as low as 3.4×10-10mol/L（S/N=3）.In addition,aiming at testing the accuracy of the proposed method,HPLC method was employed to detect chicken samples.The result of t test demonstrated that there is no significant difference between the high performance liquid chromatography（HPLC）method and the prepared ratio MIECL sensor.The constructed ratiometric MIECL sensor shows excellent performance such as high sensitivity,selectivity,reproducibility,reliability and simplicity,and provides a new platform and new idea for the analysis of sulfadiazine in chicken samples.3.A MIECL sensor was constructed based on the nickel-cobalt layered hydroxide（Ni-Co LDH）nanoarray as the substrate electrode to achieve sensitive detection of SPI.Firstly,the Ni-Co LDH nanoarray grown in situ on carbon cloth（CC）was synthesized by hydrothermal method and used as a sensing platform.The Ni-Co LDH nanoarray could support the luminescent reagent crosslinking perylenetetracarboxylic acid（PTCA）by virtue of its good electrical conductivity and large specific surface area.Then,the N-Ti3C2on the electrode modification could not only be used as an effective matrix to immobilize the luminophore PTCA,but also could be acted as an efficient coreaction accelerator to react with potassium persulfate（K2S2O8）to produce more strong oxidizing intermediate SO4·-,thereby improving the luminous efficiency of ECL.Afterwards,a non-conductive MIP film was modified on the surface of the electrode to improve the selectivity of the sensor.The constructed MIECL sensor exhibits an excellent analytical performance in the concentration range of 9.4×10-12mol/L-3.0×10-5mol/L and the detection limit could reach 3.14×10-13mol/L（S/N=3）.Eventually,the MIECL sensor has good selectivity,reproducibility and stability.This method can be applied to the detection of spiramycin,and has potential value in real sample analysis. |
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