Conducting polymers that possess good electrochemical properties, nanostructured morphology and functionality for bioconjugation are essential to realise the concept of all-polymer-based biosensors that do not depend on traditional nanocatalysts such as carbon materials, metal, metal oxides or dyes. In this research, we demonstrated a facile approach for the simultaneous preparation of a bi-functional PEDOT interface with a tunable 3D nanofibrous network and carboxylic acid groups (i.e. Nano-PEDOT-COOH) via controlled co-polymerisation of EDOT and EDOT-COOH monomers, using tetrabutylammonium perchlorate as a soft-template. By tuning the ratio between EDOT and EDOT-COOH monomer, the nanofibrous structure and carboxylic acid functionalisation of Nano-PEDOT-COOH were varied over a fibre diameter range of 15.6 ± 3.7 to 70.0 ± 9.5 nm and a carboxylic acid group density from 0.03 to 0.18 μmol cm-2. The nanofibres assembled into a three-dimensional network with a high specific surface area, which contributed to low charge transfer resistance and high transduction activity towards the co-enzyme NADH, delivering a wide linear range of 20-960 μM and a high sensitivity of 0.224 μA μM-1 cm-2 at the Nano-PEDOT-COOH50% interface. Furthermore, the carboxylic acid groups provide an anchoring site for the stable immobilisation of an NADH-dependent dehydrogenase (i.e. lactate dehydrogenase), via EDC/S-NHS chemistry, for the fabrication of a Bio-Nano-PEDOT-based biosensor for lactate detection which had a response time of less than 10 s over the range of 0.05-1.8 mM. Our developed bio-Nano-PEDOT interface shows future potential for coupling with multi-biorecognition molecules via carboxylic acid groups for the development of a range of advanced all-polymer biosensors.

中文翻译：

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可调谐的3D纳米纤维和生物功能化PEDOT网络被探索为基于导电聚合物的生物传感器。

具有良好电化学性能，纳米结构形态和生物共轭功能的导电聚合物对于实现不依赖于传统纳米催化剂（例如碳材料，金属，金属氧化物或染料）的全聚合物基生物传感器的概念至关重要。在这项研究中，我们展示了一种通过可控的EDOT和EDOT-COOH单体共聚同时制备具有可调3D纳米纤维网络和羧酸基团（即Nano-PEDOT-COOH）的双功能PEDOT接口的简便方法，使用高氯酸四丁铵作为软模板。通过调节EDOT和EDOT-COOH单体之间的比例，可以在15.6±3.7至70.0±9的纤维直径范围内改变Nano-PEDOT-COOH的纳米纤维结构和羧酸官能度。5nm和0.03至0.18μmolcm-2的羧酸基团密度。纳米纤维组装成具有高比表面积的三维网络，这有助于降低电荷转移阻力和对辅酶NADH的高转导活性，提供20-960μM的宽线性范围和0.224的高灵敏度在Nano-PEDOT-COOH50％界面处的μAμM-1cm-2。此外，羧酸基团提供锚定位点，用于通过EDC / S-NHS化学方法稳定固定NADH依赖的脱氢酶（即乳酸脱氢酶），从而制造用于乳酸检测的基于Bio-Nano-PEDOT的生物传感器。在0.05-1.8 mM范围内的响应时间少于10 s。