Investigation Of Electrochemical Sensors Based On Novel Prussian Blue And Its Nanocomposites

The electrochemical sensor is one of the frontiers in analytical scientific fields with high sensitivity, fast response, specificity and other properties, and also owns advantages such as simple sample preparation, simple portable operation, low cost and so on. Electrochemical sensor is widely applied in clinical medicine, environment and other aspects like food industry. The performance of an electrochemical sensor depends largely on its membrane materials. Nanomaterials are widely used as membrane materials for its unique physical and chemical properties in electrochemical sensors. Prussian blue stands out among various nanomaterials because of its unique structure and electrochemical properties. This thesis synthesised Prussian blue and its nanocomposites with distinctive morphologies in different ways, constructed three novel non-enzyme electrochemical sensors, set up new method for the detection of H₂O₂, and broaden the applications of prussian blue nanocomposites. The main contents are summarized and presented as follows:1. A cubic prussian blue with hollow interior was successfully synthesized by a soft-template followed by a controlled self-etching process. Studied the microstructure of the nanoparticals and its effect of on the electrochemical performance of the sensor, established a new method for H₂O₂ detection. It was found that the special structure of hollow prussian blue exhibit enhanced performances in hydrogen peroxide sensing. The amperometric experimental of HPB/Chit toward H₂O₂ was investigated, and the results show that the sensor owns a detection limit of 2 ?mol·L-1 and a sensitivity of 0.693 A·?mol·L-1?-1·cm-2 and a linear range of 8 ?mol·L-1?1.85 mmol·L-1 toward H₂O₂.2. A facile and effective electrochemical sensing technique was developed by the electrodeposition of Prussian blue on polyaniline ?PANI? coated halloysite nanotubes ?HNTs?. Then the morphology and structure of the PB/PANI/HNTs film and the effects on the electrochemical properties were studied. The studied indicated the application of PANI/HNTs improve the stability of the H₂O₂ sensor under neutral conditions. The amperometric study shows that the PB-PANI-HNTs/GCE based H₂O₂ sensor exhibits good performance with linearity in the range from 4 ?mol·L-1 to 1.06 mmol·L-1 with a sensitivity of 0.98 A·?mol·L-1?·cm-2.3. The successive electrochemical cyclic voltammetry method was used to develop electrochemical sensor based on CoHCF/ERGO. The electrochemical experimental results show that the sensor could detect H₂O₂ in the range of 10 ?mol·L-1?3.40 mmol·L-1 with a sensitivity of 0.489 A·?mol·L-1?-1·cm-2. Besides, the sensor also shows long-term stability, reproducibility and selectivity.