| With the rapid development of nanoscience and nanotechnology, electrochemical sensing methods based on nanomaterials to use in the detection of biological molecules, which have become one of hot topics in electrochemical sensor. In this thesis, many different nanomaterials have been prepared by chemical reduction, electrodeposition or biological methods. The novel electrochemical method for the detection saccharides, hydrogen peroxide (H2O2), cholesterol, tryptophan and purine were established. These results are significant to enrich the research of electrochemical sensors and provide new thoughts for the construction of high sensitive and selective electrochemical sensors. These results also broaden the application range of nanomaterials. The thesis consists of five chapters. The author’s main contributions are summarized and presented as follows:1. By electrochemical deposition, enzyme-free glucose sensors based on Chrysalidocarpus-like Co and Co NPs-GE were designed, the electrochemical behavior and electrocatalytic probility were studied. The sensor based on Chrysalidocarpus-like cobalt displayed a linearly range from2.0×10-7to1.4×10-5mol·L-1and from1.5×10-5to2.3×10-4mol·L-1. Meanwhile, the sensor based on Co NPs-GE displayed a linearly range from5.0×10-to1.4×10-3mol·L-1. Compared with Chrysalidocarpus-like Co, one-step electrodeposition of Co NPs-GE nanohybrid films had a wider linearly range.The formation of PANI and Au NPs induced by enzymatic reaction on the surface of MPA/GOD-Chit/GCE and GOx-PS/GCE was described and characterized. The new voltammetric analysis methods were presented for the detection of glucose. The experimental results exhibited that the oxidation peak currents of AuNPs and PANI were linearly related to glucose concentration from1.0×10-5～1.2×10-7mol·L-1and1.0×10-6-5.0xl0-5mol·L-1, respectively. The detection limits were4×10-6mol·L-1and5×10-7mol·L-1, respectively.Using deep eutectic solvents as solvent and template, PB NSs were fabricated. A novel glucose biosensor based on PB NSs modified electrode was constructed. The experimental results exhibited that PB NSs has excellent electrocatalytic activity toward the oxidation of glucose. The linear range for the determination of glucose was found to be9.0×10-7～1.2×10-4mol·L-1, the detection limit was3×10-7mol·L-1(S/N=3), the sensitivity was61.7A·(mmol·L-1)-1. 2. The cholesterol electrochemical biosensor based on ChOx/PANI/Au NPs and ChOx-ALP/MWCNT-Chit were fabricated, the new electrochemical methods for cholesterol were presented. The sensor based on ChOx/PANI/Au NPs displayed a linearly range from0.005to6.4mmol·L-1and a detection limit of2×10-6mol·L-1(S/N=3). Meanwhile, the sensor based on ChOx-ALP/MWCNT-Chit displayed a linearly range from0.05to2.0mmol·L-1, the sensitivity was4.65mA·(mmol·L-1)-1. The former is shown to possess superior properties of linearly range and detection limit.3. By bacteria, N2H4reduction and electrodeposition technique, silver nanoparticles (Ag NPs), tellurium nanowires (Te NWs) and poly(sulfosalicylic acid)-graphene (PSA-GE) were fabricated and their electrocatalytic behaviors were investigated, respectively. The corresponding electrochemical methods were presented for the determination of H2O2, tryptophan and purine, respectively. The experimental results exhibited that Ag NPs had electrocatalytic activity toward the oxidation of H2O2, the wider linear range was from5.0×10-5to0.12mol·L-1, the detection limit of8×10-6mol·L-1and the fast response time less than2s. Te NWs had electrocatalytic activity toward the oxidation of tryptophan, the initial potential was0.4V, the response time was less than2s, and the detection limit was1×10-8mol·L-1. PSA-GE can distinguish between adenine and guanine, showed excellent catalytic properties toward the oxidation of adenine and guanine. The linear range for the determination of adenine and guanine were found to be2.0×10-6～1.0×10-4mol·L-1and2.0×10-6～5.0×10-5mol·L-1, the detection limit was1×10-6mol·L-1and2×10-6mol·L-1, respectively. |
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