Construction Of Electrochemiluminescence Biosensors Based On Black Phosphorus Nanomaterials

Traditional electrochemiluminescence（ECL）technology has shortcomings such as fewer luminescence systems and low luminous efficiency.With the development of nanotechnology,researchers have tried to use nanotechnology to improve the luminescence behavior of traditional chemiluminescence systems.Among them,black phosphorus has been widely used in various fields due to its excellent physical and chemical properties.In this context,this thesis attempts to study the new application of black phosphorus in the field of electrochemiluminescence.The main research work includes the following aspects:1.Black phosphorus nanomaterials as ECL quencher:Aqueous black phosphorus nanosheets（BPNSs）were synthesized by the ultrasonic-assisted liquid phase stripping method and characterized by transmission electron microscopy（TEM）,Raman spectroscopy and other techniques.Studies have found that resonance energy transfer（RET）can occur between BPNSs and luminol,which can quench the ECL signal of luminol.The coating of BPNSs by protamine can block the process of energy resonance transfer,and establish a biosensor that can be used indirectly to sensitively detect the content of trypsin,and provide some reference value in new applications for exploring black phosphorus in the field of electrochemiluminescence.2.Black phosphorus nanomaterials as ECL co-reactants:Black phosphorus quantum dots were experimentally synthesized and modified their surfaces with polyethylene glycol（PEG-BPQDs）to improve the stability of the materials,and characterized them by TEM,infrared spectroscopy.The study found that ruthenium bipyridyl nanoflowers（Ru NDs）have a strong cathodic luminescence phenomenon in potassium persulfate solution,and BPQDs can be used as the anodic co-reactant of Ru NDs to make Ru NDs exhibit bipolar luminescence on BPQDs modified electrodes.The ferrocene modified at the DNA end can simultaneously quench the bipolar luminescence phenomenon of Ru NDs,and a bipolar aptasensor was constructed to detect the content of MUC1 protein.Compared with the one-polar ECL system,the sensor has greatly improved detection accuracy,and it also provides an example for constructing a bipolar luminescence system with a single luminophor.3.Black phosphorous nanomaterials as ECL emitters:Black phosphorous nanosheets and graphite carbon nitride（g-C₃N₄）were experimentally synthesized and performed TEM and energy spectrum（EDS）characterization.Studies have found that BPNSs and g-C₃N₄can be used as ECL emitters respectively,and exhibit the luminescence of anode and cathode under the conditions of different co-reactants.The hydrogen peroxide produced during the oxidation of cholesterol will bring different signal changes to the anode and cathode to establish an indirect method for detecting cholesterol content.This method further improves the sensitivity,accuracy and anti-interference of the detection by constructing a bipolar ECL signal,and at the same time provides a new idea for constructing a bipolar electrochemiluminescence sensing platform.