Construction Of Electrochemiluminescence Immunosensors Based On Functionalized Molybdenum Disulfide Nanomaterials And Its Applications

Electrochemiluminescence（ECL）biosensor is developed by the combination of molecular recognition components and ECL.It is an attractive detection platform with high sensitivity,wide linear range,fast analysis speed,and good selectivity.It has been widely used in the field of environmental pollution monitoring,food safety analysis and the judgment of disease.In the paper,combining high specificity of the immunoreactions,a series of new ECL sensing platforms were designed for sensitive and accurate detection of disease markers based on the excellent chemical and physical properties of functionalized nanomaterials.The excellent ECL properties of CdS-MoS₂,MoS₂ gold nanoparticles（MoS₂-Au NPs）nanocomposites,and MnCO₃ nanomaterials were synthesized.Integrating with enzyme signal amplification strategy and co-reaction accelerator of CuS-Ag NPs,ECL biosensor platforms for sensitive detection of cardiac troponin I（cTnI）,prostate specific antigen（PSA）and myoglobin（Myo）were constructed.The main investigations are as follows:1.Label-free electrochemiluminescence immunosensor for the determination of cardiac troponin I using a cadmium sulfide–molybdenum（IV）sulfide nanocomposite modified glassy carbon electrodeA label free ECL immunosensor for the determination of cTnI was developed using CdS-MoS₂ composites as the electrochemiluminescence emitters.The CdS-MoS₂composites were synthesized by a hydrothermal method and used for the construction of the electrochemiluminescence biosensing platform.For the fabrication of the immunosensor,CdS-MoS₂ composites,chitosan,cTnI antibodies,and bovine serum albumin were consecutively assembled on the glass carbon electrode.Under the optimum conditions,the label free electrochemiluminescence determination of cTnI was obtained.Due to the excellent electrochemiluminescence performance of CdS-MoS₂ composites and high specificity of the immunoreactions,the sensor shows satisfactory selectivity and high sensitivity for cTnI determination.The detection limit was 1.0 pg/mL and the linear range was from 5.0 pg/mL to 100.0 ng/mL.Moreover,the method was successfully used to determine cTnI in human serum samples with recoveries between 85.4%and 111.0%,the results were in good agreement with the reference values provided by the Xinyang Central Hospital.The relative standard deviation values（RSDs）were less than 7.9%.This label-free immunosensor possesses many merits,including a simple sensing process,good electrochemiluminescence performance of the CdS-MoS₂ composites,and high flexibility for extending the strategy for the determination of other biomarkers.2.Construction of electrochemiluminescence sensing platform with in situ generated coreactant strategy for sensitive detection of prostate specific antigenA sandwich-type ECL platform was fabricated for sensitive detection of PSA by using Au NPs decorated MoS₂ as electrode material and SiO₂ nanoparticles labeled with secondary antibody and glucose oxidase as signal probes.Owing to the excellent conductivity and large surface area of MoS₂-Au NPs,the fast electron transfer process and the immobilization of numerous biomolecules can be achieved.The GOD labeled signal probes can realize the in situ generation of H₂O₂ as coreactant to amplify the ECL intensity of luminol.The developed immunosensor shows a linear relationship of0.50 pg/mL–10.0 ng/mL and a detection limit of 0.20 pg/mL for PSA detection.The immunosensor also has been successfully applied for the analysis of PSA in human serum samples,compared with the standards refer offered by Xinyang Central Hospital,the result is consistent,and the RSDs are no more than 6.8%.Furthermore,the proposed strategy shows great application prospects for determination of other biomarkers in biological samples.3.CuS-Ag nanomaterials as co-reaction accelerator for construction electrochemiluminescence sensing platform and sensitive detection of MyoThe introduction of co-reaction accelerator CuS-Ag NPs resulted in the production of a large number of intermediates SO₄^·-and leading to signal amplification.The ECL sensor for sensitive Myo detection was constructed.MnCO₃ as luminescent material,electrodeposited gold nanoparticles promote electron transfer and enhance luminous intensity effectively.After layer-by-layer modification,the probes of anti-Myo-MoS₂-CuS-Ag NPs are immobilized on the sensing interface.MoS₂ has a large specific surface area and can be loaded with a large number of CuS-Ag NPs.The carried CuS-Ag NPs to generate more strong oxidant intermediate SO₄^·-,thereby enhancing the ECL strength of MnCO₃.In this system,MoS₂ provides a rugged carrier frame and CuS-Ag NPs has excellent catalytic performance,enabling the construction of a sensor platform for Myo sensitive detection.