Fabrication And Application Of Electrochemiluminescence Sensors Based On Green Synthesized Nano-materials

Electrochemiluminescence(ECL) is a process of converting electrochemical energy into luminous energy via an electron transfer reaction at the surface of electrode. Recent years have witnessed the great development of ECL sensor as a platform for the analytical processes in many fields, which includes pharmaceutical analysis, immunoassay, DNA analysis as well as clinical analysis. Green nanomaterials are attractive in the developement of biosensors due to their homogeneity of particle size, excellent electroconductibility and large specific surface area as well as abundant functional groups, favorable biocompatibility. ECL sensors based on green synthesized nanomaterials demonstrated very promising properties of signal amplification labels in electrochemical applications. Furthermore, they could conjugate with bioproteins and biomolecules. In this paper, carbon nanospheres(CNPs), Ag@BSA microspheres(Ag@BSA) and Flower-like Au@BSA nanoparticles(Au@BSA) were used for the construction of ECL biosensors. The major contents are displayed as fllows:(1) In this work, we have frabricated a novel electrochemiluminescence(ECL) drug sensor for sensitive atropine determination based on Ru(bpy)32+/carbon nanospheres/Nafion composite film. The carbon nanospheres(CNPs) with high surface area、good electrical conductivity and favorable biocompatibility in composite film were obtained through a hydrothermal method. Moreover, owing to ion-exchange and membrane building feature of nafion, we used nafion to immobilize Ru(bpy)32+, resulting in abundant adsorption of Ru(bpy)32+. As a result, the as-prepared ECL sensor can be used to quantitative detection of atropine. Moreover, the ECL sensor is able to be used to detect atropine in real samples with satisfying recovery. This preliminary method provided an effective strategy for atropine detection, which showed promising applications in drug analysis.(2) In the protocol, we developed an effective sandwiched ECL immunosensor for CA19-9 ultrasensitive detection based on luminol-Au@BSA nanoparticles. Herein, we used MAGCNTs with large surface area and favorable electroconductibility as the nanoscale anchorage substrate and luminol-Ag@BSA-Ab2 as the signal probe. After incubation with CA19-9, luminol-Ag@BSA-Ab2 could be bound to the surface of electrode through sandwich-type immunoreaction, and an extremely enhanced signal of the ECL immunosensor could be received for synergistic amplification factors of MAGCNTs and Ag@BSA microspheres. The above-mentioned immunosensor exhibited favorable analytical performance for CA19-9, paving the way for a novel approach in determination of other biomolecules and protein.(3) A novel electrochemiluminescence(ECL) immunosensor has been designed for ultrasensitive determination of tumor marker carcinoembryonic antigen(CEA) by using multifunctionalized Flower-like Au@BSA nanoparticles as biosensing interface. In this work, Flower-like Au@BSA Nanoparticles with large surface area, favorable electrical conductivity and excellent biocompatibility were not only employed as an electrochemiluminescence interface but also as ideal multifunctional carriers to effectively immobilize numerous luminol molecules and CEA capture antibodies(Anti-CEA) acted as signal probe and molecule recognition probe, respectively. In addition, Au NPs were electrodeposited onto the glassy carbon electrode(GCE) surface to construct an outstanding base for this immunosensor, which could further promote the electron transfer and load a large amount of multifunctionalized Flowerlike Au@BSA nanoparticles. Under the optimal conditions, ECL intensity of the immunosensor decreased linearly with the logarithm of CEA concentration ranging from 0.001 to 200 ng/m L with a low detection limit of 0.0003 ng/m L(S/N=3). The asprepared sensing technique exhibited high performances in reproducibility, stability, and specificity. Furthermore, the developed immunoassay has been applied to the detection of CEA in real serum samples with satisfactory results, indicating that the proposed strategy providing an alternative scheme for other clinically important biomarkers assay.