Electrochemical Detection Of Tumor Markers And Small Molecules Based On Novel Metal-organic Coordination Polymers

In recent years, the early detection of malignant tumors has become a hot issue. It is difficulty to use the traditional technology to detection of malignant tumors in the early.Nucleic acid aptamers are a variety of advantages that can target a variety of tumor markers with high specificity, high affinity and simple modification, rich target targets, and easy synthesis which can be used as an ideal tumor targeting recognition molecule. At the same time, metal-organic frameworks (MOFs) complexes are polymerized through metal ions or metal clusters and organic ligands through the coordination bond to form a periodic,infinite network of polymer porous structure. It has a promising prospect in gas storage and separation, photoelectrochemical sensors, catalysts and so on because of its porous structure, adjustable pore size, multiple functions, and special optical and magnetic properties and many other advantages. Based on this, this paper aims to develop a new type of malignant tumor early detection method, through the metal organic polymer binding of nucleic acid aptamers as a new tumor targeting recognition molecules, and electro-chemical biosensor to amplify the signal to achieve the effect of detection of tumor marker. The application of functional MOFs also applied to hydrogen peroxide, AA and other small molecules detection, including the following parts of the content.Firstly, thionine (Thi) and dimethyl 1, 8-anthracenedicarboxylate (Dada) were used as ligands, transition metal copper and cobalt as coordination centers to synthesis two new metal-organic polymers Cu-Dada and Co-Thi, then to determine the molecular formula.The metal organic polymers Cu-Dada and Co-Thi were combined with Sgc8c to produce Cu-Dada-Sgc8c and Co-Thi-Sgc8c.The electrochemical biosensor based on Cu-Dada-Sgc8c and Co-Thi-Sgc8c were used to detect tumor marker PTK7K. The experimental results showed that the linear detection ranges of the Cu-Dada-Sgc8c/GCE for PTK7K is 6.25×10-7-3.75×10-6 mg mL-1, the detection limit is 1.5 × 10-8 mg mL-1, and the sensitivity is 3.87mA mL mg-1 cm-2. The linear detection ranges of the Co-Thi-Sgc8c/GCE for PTK7K is 1.25 × 10-5-2 × 10-4 mg mL-1, with detection limit of 1.67 × 10-6 mg mL-1, sensitivity of 1.66 mA mL mg-1 cm-2.Cu-Dada/GCE was use to construct ascorbic acid, nitrite and hydrogen peroxide electrochemical sensors. Experimental results show that, the linear range of Cu-Dada to detect hydrogen peroxide is 5×10-7-2.6×10-3 M. It has a high sensitivity of 199.6 mA mol-1 L cm-2, the lowest detection limit of 2.6×10-7 M. After the application of carbon nanotubes,we made Cu-Dada/MWCNTs/GCE. The linear range of the sensor is 5×10-7-1.8×10-1 M,the sensitivity of the sensor is 424.3 mA mol-1 L cm-2, the lowest detection limit was 2.4×10-6 M. Doped carbon nanotubes increased approximately doubled the electrode sensitivity, linear range has also been expanded, anti-jamming performance has also been enhanced. Cu-Dada can be said to be an excellent power of hydrogen peroxide sensor material. The linear range of Cu-Dada/GCE to detect ascorbic acid is 1.6x10-5-2.2×10-3 M.This sensor detects ascorbic acid with a sensitivity of 37.5 mA mol-1 L cm-2, the lowest detection limit of 1.37×10-6 M. The linear range of Cu-Dada/GCE to detect sodium nitrite is 5×10-5-1.2×10-1 M, the sensitivity of the sensor is 2.1 mA mol-1 L cm-2, the detection limit was 1.6x10-5 M. Cu-Dada/MWCNTs/GCE's performance improves a lot, the linear range is 5×10-5-9.8×10-3 M. The sensitivity of the sensor is 76 mA mol-1 L cm-2, the detection limit is 7.3×10-6 M.