Study On Several Electrochemical Sensors Based On Phenylboronic Acid And Carbon Material

Phenylboronic acid and its derivatives are involved in many chemical reactions as intermediate in organic chemistry, and they also play important roles in the field of analytical chemistry and biology, such as enzyme inhibitors, agricultural fungicide, anticancer reagents and chemiluminescence enhancement reagent. The most important application of phenylboronic acid is the linkage with polyol.Novel carbon nanomaterials have been a hot spot materials at present. They have excellent physical and chemical properties, and have great potential applications in many areas. Novel carbon nanomaterials can be prepared by modifying the existing carbon nanomaterials or combining existing carbon nanomaterials with other materials. In recent years, some novel carbon nanomaterials have been reported and used in many areas, such as chemistry and biology, etc.Based on the properties of phenylboronic acid and novel carbon nanomaterials, the sensors have excellently analytical properties and potential applications. The electrochemical sensors have attracted increasing attention owing to its remarkable features of high sensitivity, simple and inexpensive instrumentation, low fabrication cost, fast response, and portability. In this thesis, we investigated the application of phenylboronic acid and novel carbon nanomaterials in electrochemical sensor. The main point is summarized as follows:(1) The graphene oxide-phenylboronic acid (GO-PBA) hybird material was obtained from the coupling reaction between graphene oxide (GO) and phenylboronic acid (PBA). Since PBA can reversibly bind with1.2-diols, a novel amplified impedimetric DNA sensor based on GO-PBA modified electrode for sensitive detection of bleomycins (BLMs) was developed. In the presence of BLMs, the DNA probe on the modified electrode is found to undergo oxidative transformation to be selectively cut off to release GO-PBA and DNA fragments, resulting in a significant Ret decrease. The developed GO-PBA/DNA/Au electrode exhibits good analytical characteristics in the detection of BLMs, such as low detection limit, good stability, reproducibility, anti-interference ability, selectivity and particularly a wide linear range.(2) A novel electrochemical DNA sensor for detection of BLMs based on dopamine-capped gold nanoparticle (DA-AuNPs) and4-mercaptophenyl boronic acid-capped gold nanoparticle (MBA-AuNPs) as a dual-amplification factor modified Au electrode was developed. According to the DNA probe on the modified electrode is was cut off to cause the change of current signal through using differential pulse voltammetry (DPV) method, the developed DA-AuNPs/MBA-AuNPs/DNA/Au electrode exhibits good analytical characteristics in the detection of BLMs, such as low detection limit and wide linear range, reproducibility and good stability. The electrochemical DNA sensor has a novel material and a simple preparation method; it is of great significance to the development and application of DNA sensors.(3) An electrochemical enzyme sensor for detection of hydrogen peroxide (H2O2) based on MBA-AuNPs connecting with horseradish peroxidase (HRP) and poly (dopamine)-multiwalled carbon nanotube (PDA-MWCNTs) modified glassy carbon (GC) electrode was developed. The morphology and structrue of PDA-MWCNTs and HRP/MBA-AuNPs/PDA-MWCNTs hybird materials were characterized by Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscope (SEM). The assembly process of sensor was characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Under the optimum conditions, the electrochemical enzyme sensor for detection of H2O2exhibits good analytical characteristics, such as low detection limit and wide linear range, reproducibility, good stability and selectivity.(4) A new electrochemical sensor for detection of catechol (CC) based on3-aminophenylboronic acid (3-APBA) binding with3,4,9,10-perylene tetracarboxylic acid functionalized carbon nanotubes (PTCA-CNTs) modified GC electrode was developed. The PTCA-CNTs was characterized by FT-IR spectroscopy. The PTCA-CNTs hybird materials could bind with a large number of3-APBA molecules to improve the sensitivity of the sensor. The electrochemical signal has a change before and after the modified electrode binding with CC. According to that, the developed3-APBA/PTCA-CNTs/GC electrode exhibits good analytical characteristics in the detection of CC, such as low detection limit, good stability, reproducibility, anti-interference ability, selectivity and particularly a wide linear range. The electrochemical sensor detection of CC has been successfully applied in the realistic samples.(5) Because of3-APBA can be irreversibly oxidized with3-aminophenol by H2O2, an electrochemical non-enzyme sensor for high selectively detecting H2O2was developed. The assembly process of sensor was characterized by EIS and DPV. And the experimental parameters and the preparation conditions were optimized. Under the optimum conditions, the electrochemical3-APBA/4-ABA/GC electrode exhibits good analytical characteristics, such as wide linear range, low detection limit, reproducibility and good stability. The selectivity of the developed H2O2sensor has been evaluated in the presence of these interferents, such as nitrite ion (NO2-), superoxide anion (O2-), hydroxyl radical (-OH), uric acid (UA), ascorbic acid (AA) and dopamine (DA). Additionally, the sensor could be applied to the determination of the human serum sample.(6) A novel electrochemical sensor based on nitrogen doped porous carbon nanopolyhedrons-multiwalled carbon nanotube (N-PCNPs-MWCNTs) hybird materials modified GC electrode for simultaneous electrochemical determination of hydroquinone (HQ), CC and resorcinol (RE) was developed. The N-PCNPs-MWCNTs hybird materials were characterized by SEM. The sensor was characterized by CV, which indicated the feasibility of N-PCNPs-MWCNTs/GC electrode for detection HQ, CC and RE. Optimization of measurement parameters such as the amount of N-PCNPs-MWCNTs hybird materials and pH value were studied in detail. Under the optimum conditions, the developed N-PCNPs-MWCNTs/GC electrode exhibits good analytical characteristics, such as low detection limit, wide linear range, reproducibility and good stability. The sensor could be applied for simultaneous electrochemical determination of HQ, CC and RE. And it has good simultaneous detection ability in the linear range from5.0μM to60μM. Moreover, this electrochemical sensor has potential applications in the evaluation of realistic samples.