Glucose and urea enzymatic biosensors were fabricated. One-step electrochemical immobilization process was used to produce thin polyaniline films with entrapped enzymes. Chronopotentiometric analysis, scanning electron microscopy, electrochemical impedance spectroscopy and optical reflectance spectroscopy were used to determine the structure-property relationship of the functionalized polymeric thin films. The device has a recognition stage connected to a potentiometric field-effect-transistor stage and is based on the measurement of microenvironment pH variation or locally produced ions. Optimization of biosensor fabrication and effective measurement conditions were performed. The optimized films presented sensitivity, linearity and detection range to glucose of 14.6 ± 0.4 mV/decade, 99.8% and from 10⁻⁴ M to 10⁻¹ mol/L. Two different biosensors were produced based on the enzymatic reaction of urea with selectivity to ammonium or hydroxyl ions. For ammonium ion selective film, the sensor’s parameters were 14.7 ± 0.9 mV/decade, 98.2% and from 10⁻⁵ to 10⁻¹ mol/L. For the hydroxyl ion selective film, the same parameters were 7.4 ± 0.5 mV/decade, 98.1% and from 10⁻⁵ to 10⁻¹ mol/L. The change in the oxidation state of the polymeric matrix explains: i) the large loss of functionality of glucose biosensor in time, ii) the conservation of functionality to the hydroxyl ions for urea biosensor and iii) the selectivity variation of the ammonium ion selective urea biosensor. The results indicate that the polymeric matrix has indeed changeable selectivity, what can be applied in different situations for biosensors production.

中文翻译：

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一步电化学固定化生产的酶促功能化聚苯胺薄膜及其在葡萄糖和尿素电位生物传感器中的应用。

制备了葡萄糖和尿素酶生物传感器。一步电化学固定化工艺用于生产包埋有酶的聚苯胺薄膜。计时电位分析，扫描电子显微镜，电化学阻抗谱和光学反射光谱被用来确定功能化的聚合物薄膜的结构-性质关系。该设备具有一个与电位场效应晶体管级相连的识别级，并且基于微环境pH值变化或局部产生的离子的测量结果。优化了生物传感器的制造和有效的测量条件。优化的薄膜对葡萄糖的灵敏度，线性和检测范围为14.6±0.4 mV /十年，99.8％和10 ^-4 M至10 ^-1  mol / L。基于脲对铵或氢氧根离子的酶促反应，产生了两种不同的生物传感器。对于铵离子选择性薄膜，传感器的参数为14.7±0.9 mV / decade，98.2％和10 ^-5至10 ^-1  mol / L。对于氢氧离子选择性膜，相同的参数为7.4±0.5 mV /十倍，98.1％和10 ^-5至10 ^-1 摩尔/升。聚合物基体氧化态的变化说明：i）葡萄糖生物传感器的功能性大量丧失，ii）尿素生物传感器的氢氧根离子的功能保守性，iii）铵离子选择性尿素的选择性变化生物传感器。结果表明，聚合物基质确实具有可变的选择性，可以在不同情况下应用于生物传感器的生产。