This special issue of Macromolecular Bioscience highlights the recent advance in organic electronic/ionic conductors and related devices for bioelectronic applications. Materials for bioelectronics which are supposed to interface effectively with biological systems should meet certain chemical, mechanical, and electrical/electrochemical requirements, and importantly, do so in the aqueous phase at physiological conditions.^[1-3] Therefore, along with the understanding biological processes, multidisciplinary research efforts have been pursued to develop suitable materials with efficient signal‐transduction performance as well as long‐term biocompatibility. Recently, several polymeric materials have drawn much attention in the research field of bioelectronics due to their relatively low moduli in combination with sufficient ionic and/or electronic conductivities.^[4-6] Particularly, conjugated polymers with mixed ionic/electronic conduction properties have been successfully utilized for amplifying biological signals efficiently. For examples, the sophisticated macromolecular bioelectronics devices have been demonstrated for biomolecular sensing,^[7-10] electrophysiological signal analysis and stimulation,^[11-14] while ion/drug injection devices have been developed for the diagnosis and treatment of various human disease.^[15-18] It is expected that the long‐term biocompatibility and the improved functionality of macromolecular bioelectronics materials to target organs and tissues will find a myriad of different biomedical applications in the near future.

In this special issue, critical reviews and original research articles deal with the latest development of materials, processes, and characterizations in the field or macromolecular bioelectronics. Various types of bioelectronics materials are discussed: conductive polymers, liposome‐conductive polymer complex, and iongels. Additionally, recent studies on novel polymeric mixed conductor design, efficient printing processes, self‐healing properties, and the effect of anions and additives on electropolymerization are presented, while their applications to biomolecular sensors, point‐of‐care devices, neural stimulation, and mechanotransducers are considered. Therefore, we expect that this special issue will not only offer the insight on material development but also valuable ideas for advanced device applications in the research field of bioelectronics.

Heeney and colleagues report on the modification of conjugated polymers with glycol sidechains after polymerization with the minimal change in their energetics and band gaps.^[19] Hydrophilic side chains were added by the nucleophilic aromatic substitution reaction on fluorinated benzothiadiazole within a conjugated polymer backbone. The optical, electrical, and thermal characterizations of synthesized polymers revealed that the length of glycol sidechain has a direct impact on the surface wettability of resultant films and their solubilities in polar solvents. This study demonstrates a facile way to modulate the surface wettability and solubility of conjugated polymer‐based bioelectronics devices; both are critical for ion penetration and stability in hydrated enviroments.

Mawad and colleagues describe the one‐step fabrication approach of conjugated polymer‐liposome complexes for bioimaging, drug delivery, and photothermal therapy.^[20] Polyaniline (PANI) was synthesized by oxidative polymerization in the presence of phytic acid and 1,2‐dioleoyl‐sn‐glycero‐3‐phosphatidylcholine vesicles to produce the aqueous suspension of PANI‐liposome complexes. These complexes exhibited the appropriate ranges of electrical conductivity and cell viability suitable for electrophysiological modulation of cells or electroresponsive tissues without the disruption of liposome bilayer structures. With this study the authors demonstrate the feasibility of a novel class of materials based on conjugated polymer‐liposome complexes which can be used for electroactive biointerfaces.

Mecerreyes and colleagues report on the ion‐conducting soft iongels with hyperelasticity and thermo‐reversibility.^[21] The iongels were fabricated by supramolecular crosslinking between plant‐derived phenolic compound such as gallic acid, pyrogallol, tannic acid, and hydroxyl‐rich poly(vinyl alcohol) (PVA) in the presence of ionic liquids. The resultant iongels showed thermo‐reversible property with transition temperatures ranging from 87 to 110°C, which is suitable for printing applications. In addition, the ion‐conductive gel structures were sufficiently flexible and tolerate large elastic deformations over 40% with the full recovery capability, proving their potentials in the research field of bioelectronics.

Parlak and colleagues report a review article on bacterial sensing and biofilm monitoring for the purpose of infection diagnosis.^[22] This review article covers many different technologies related to sensing bacteria and bacterial biofilms, ranging from electrochemical sensing via synthetic or natural recognition to algorithm‐based optical sensing to tailor‐made optotracing. They also address how fast and accurate bacterial sensing and biofilm monitoring could be achieved, and how these different sensing concepts could be translated to infection diagnostics. Finally, they describe overall advances to date in translational analytical efforts made at the level of an individual bacterial cell to bacterial community.

Jung and colleagues report on the on‐site organic preamplifier with a three‐dimensional structure on plastic substrates for lactate sensing.^[23] The preamplifier constructed in the form of complementary inverter, was fabricated by vertical stacking complementary transistors with the shared gate. Subsequently, the lactate sensor was prepared by functionalizing the extended gate with lactate oxidase, resulting in the detection of lactate in human sweat (20–60 mM) with high sensitivity (6.82 mV/mM) due to the excellent amplification performance. Moreover, the integrated device structure doubles the number of transistors per unit area, leading to the substantial cost reduction. This research presents the state‐of‐the‐art biomolecular sensing in terms of device integration and noise reduction, which have been bottleneck toward realizing wearable and disposable bioelectronics.

Cicoira and colleagues report on the water‐enabled self‐healing properties of poly(3,4‐ethylene‐dioxythiophene):polystyrene sulfonate (PEDOT:PSS).^[24] PEDOT:PSS films processed in the presence of crosslinker, and PEDOT:PSS films post‐treated with sulfuric acid were employed to study the effect of PSS concentration on self‐healing. In comparison, PEDOT:tosylate (TOS), PEDOT:trflate (OTf), and PEDOT:ClO₄ films were prepared via electrochemical polymerization, and the effect of organic/inorganic dopants on self‐healing were investigated. Both crosslinking and PSS removal weakened or eliminated the water‐enabled self‐healing behavior of PEDOT:PSS. In electrochemically polymerized PEDOT, organic dopants have superior water‐enabled healing compared inorganic dopant the reduced swelling ability. This research shows the future potentials of self‐healable organic bioelectronics based on PEDOT:PSS which is one of the most utilized polymeric mixed conductors.

Kim and colleagues report on the printable ionic mechanotransducer array (IMA) as bio‐inspired mechanoreceptors.^[25] Using ionic thermoplastic polyurethane solutions, the ionic mechanotransduction channel was fabricated in the form of a peizocapacitive ionic mechanosensor. The resultant IMAs showed high sensitivity (2.65 nF kPa⁻¹) and good resolution (13.22 cm⁻²), while those with versatile shapes of artificial mechanotransducers could be printed by controlling the printing process parameters. This research opens up a new venue towards soft and stretchable platform of sensor arrays.

Hamedi and colleagues report the woven textile diagnostic devices based on commercially produced yarns without any modification or cleaning processes.^[26] Three‐electrode sensing devices were fabricated by weaving the Coolmax® yarns (originally developed for sweat‐wicking sportswear). They confirmed that Au‐coated multifilament yarns exhibit good functionalization and electrochemical activity comparable to cleaned Au disk electrodes. Furthermore, they demonstrated that these three‐electrode devices are capable of detecting clinically relevant concentrations of glucose in human sweat, suggesting the possibility of manufacturing wearable biomolecular sensors by using conventional mass‐production materials and facilities without complicated modifications.

Yoon and colleagues report a review article on the design principles of conjugated polymers for the purpose of bioelectronics.^[27] They reviewed the fundamental understanding of polymeric mixed conductors, the recent advance in enhancing their ionic and electrical conductivity, the limitation in long‐term material/performance stability, and their practical applications as biosensors based on organic electrochemical transistors. In particular, the importance of structure‐property relation in mixed electronic/ionic conductivity and their interplay were discussed in detail. Finally, key strategies are suggested for developing novel polymeric mixed conductors that may exceed the trade‐off between device performance and stability.

Inal and colleagues report the effect of dopants and additives on the electrochemical performance and operational stability of electropolymerized conjugated polymers.^[28] Copolymers based on 3,4‐ethylenedioxythiophene (EDOT) and its hydroxyl‐terminated counterpart (EDOTOH) were electropolymerized in water in the presence of various counter anions and additives. Among various polymers developed, the copolymer p(EDOT‐ran‐EDOTOH) doped with ClO₄ in the presence of ethyleneglycol showed high specific capacitance and electrochemical stability. The resultant microelectrode arrays based on this polymer showed appropriate cell viability, stimulating/recording performance, and device operation stability, providing the insight to the effect of dopants and additives on the electrochemical performance and device stability of electropolymerized conjugated polymers.

These ten articles presented in this special issue illuminate the state‐of‐the‐art technologies and the future perspectives in the research field of macromolecular bioelectronics. The in‐depth understanding of their unique characteristics and feasibility to the viable bioelectronic devices will enable the breakthrough toward designing novel polymeric materials suitable for more sophisticated applications. Moreover, the continuing research efforts on engineering novel device architecture, guaranteed operational stability, scalable processability, and cost‐saving manufacturing technology are essential to enable the early commercialization of macromolecular bioelectronics. Finally, we expect that the development of future bioelectronics based on the in‐depth understanding of fundamental material properties and the state‐of‐the‐art technologies on device fabrication and manufacturing processes will rapidly create a paradigm shift in patient diagnosis and therapeutics.

本期《大分子生物科学》特刊重点介绍了有机电子/离子导体和生物电子应用相关设备的最新进展。应该与生物系统有效接口的生物电子材料应满足某些化学、机械和电/电化学要求，重要的是，在生理条件下在水相中这样做。^{[ 1-3 ]}因此，随着对生物过程的理解，多学科研究努力开发具有有效信号转导性能和长期生物相容性的合适材料。最近，几种聚合物材料由于其相对较低的模量以及足够的离子和/或电子电导率而在生物电子学研究领域引起了广泛关注。^{[ 4-6 ]}特别是，具有混合离子/电子传导特性的共轭聚合物已成功用于有效放大生物信号。例如，复杂的大分子生物电子器件已被证明用于生物分子传感，^{[ 7-10 ]}电生理信号分析和刺激，^{[ 11-14 ]}而离子/药物注射装置已被开发用于各种人类疾病的诊断和治疗。^{[ 15-18 ]}预计在不久的将来，大分子生物电子材料对靶器官和组织的长期生物相容性和改进的功能将发现无数不同的生物医学应用。

在本期特刊中，批判性评论和原创研究文章涉及该领域或大分子生物电子学领域的材料、工艺和表征的最新发展。讨论了各种类型的生物电子材料：导电聚合物、脂质体-导电聚合物复合物和离子凝胶。此外，还介绍了最近关于新型聚合物混合导体设计、高效印刷工艺、自愈特性以及阴离子和添加剂对电聚合的影响的研究，同时介绍了它们在生物分子传感器、即时护理设备、神经刺激和考虑了机械换能器。所以，

Heeney 及其同事报告了聚合后用乙二醇侧链对共轭聚合物进行改性，其能量和带隙变化最小。^{[ 19 ]}亲水侧链是通过在共轭聚合物骨架内氟化苯并噻二唑上的亲核芳香取代反应添加的。合成聚合物的光学、电学和热学特性表明，乙二醇侧链的长度直接影响所得薄膜的表面润湿性及其在极性溶剂中的溶解度。该研究展示了一种调节基于共轭聚合物的生物电子器件的表面润湿性和溶解性的简便方法；两者对于水合环境中的离子渗透和稳定性都至关重要。

Mawad 及其同事描述了用于生物成像、药物递送和光热疗法的共轭聚合物-脂质体复合物的一步制造方法。^{[ 20 ]}在植酸和 1,2-二油酰-sn-甘油-3-磷脂酰胆碱囊泡存在下，通过氧化聚合合成聚苯胺 (PANI)，以制备 PANI-脂质体复合物的水悬浮液。这些复合物表现出适当范围的电导率和细胞活力，适用于细胞或电反应组织的电生理调节，而不会破坏脂质体双层结构。通过这项研究，作者证明了一类基于共轭聚合物-脂质体复合物的新型材料的可行性，该材料可用于电活性生物界面。

Mecerreyes 及其同事报告了具有超弹性和热可逆性的离子导电软离子凝胶。^{[ 21 ]}在离子液体存在下，通过植物来源的酚类化合物如没食子酸、连苯三酚、单宁酸和富含羟基的聚乙烯醇 (PVA) 之间的超分子交联制备了离子凝胶。所得离子凝胶表现出热可逆性，转变温度范围为 87 至 110°C，适用于印刷应用。此外，离子导电凝胶结构具有足够的柔韧性，可承受超过 40% 的大弹性变形并具有完全恢复能力，证明了其在生物电子学研究领域的潜力。

Parlak 及其同事报告了一篇关于以感染诊断为目的的细菌传感和生物膜监测的评论文章。^{[ 22 ]}这篇综述文章涵盖了许多与传感细菌和细菌生物膜相关的不同技术，从通过合成或自然识别的电化学传感到基于算法的光学传感到定制的光追踪。他们还解决了如何快速和准确地实现细菌传感和生物膜监测，以及如何将这些不同的传感概念转化为感染诊断。最后，他们描述了迄今为止在单个细菌细胞到细菌群落水平上进行的转化分析工作的总体进展。

Jung 及其同事报告了在塑料基板上具有三维结构的现场有机前置放大器，用于乳酸传感。^{[ 23 ]}以互补反相器形式构建的前置放大器是通过垂直堆叠具有共享栅极的互补晶体管制造的。随后，通过用乳酸氧化酶对扩展门进行功能化来制备乳酸传感器，由于优异的放大性能，从而以高灵敏度（6.82 mV/mM）检测人体汗液（20-60 mM）中的乳酸。此外，集成器件结构使单位面积的晶体管数量增加了一倍，从而大大降低了成本。这项研究在设备集成和降噪方面展示了最先进的生物分子传感，这一直是实现可穿戴和一次性生物电子产品的瓶颈。

Cicoira 及其同事报告了聚（3,4-乙烯-二氧噻吩）：聚苯乙烯磺酸盐（PEDOT：PSS）的水自愈特性。^{[ 24 ]}在交联剂存在下处理的 PEDOT:PSS 薄膜和用硫酸后处理的 PEDOT:PSS 薄膜被用来研究 PSS 浓度对自修复的影响。相比之下，PEDOT:甲苯磺酸盐 (TOS)、PEDOT:trflate (OTf) 和 PEDOT:ClO ₄通过电化学聚合制备薄膜，并研究了有机/无机掺杂剂对自修复的影响。交联和 PSS 去除都削弱或消除了 PEDOT:PSS 的水自愈行为。在电化学聚合的 PEDOT 中，与无机掺杂剂相比，有机掺杂剂具有更好的水使愈合能力，但溶胀能力降低。这项研究显示了基于 PEDOT:PSS 的自修复有机生物电子学的未来潜力，PEDOT:PSS 是最常用的聚合物混合导体之一。

Kim 及其同事报告了可打印的离子机械换能器阵列 (IMA) 作为受生物启发的机械感受器。^{[ 25 ]}使用离子热塑性聚氨酯溶液，离子机械转导通道以pezocapacitive 离子机械传感器的形式制造。由此产生的 IMA 显示出高灵敏度 (2.65 nF kPa ^-1 ) 和良好的分辨率 (13.22 cm ^-2 )，而那些具有多种形状的人工机械换能器可以通过控制印刷工艺参数进行印刷。这项研究为传感器阵列的柔软和可拉伸平台开辟了新的领域。

Hamedi 及其同事报告了基于商业生产的纱线的机织纺织品诊断设备，无需任何修改或清洁过程。^{[ 26 ]}三电极传感装置是通过编织 Coolmax® 纱线（最初开发用于排汗运动服）制成的。他们证实，Au 涂层复丝纱线表现出与清洁的 Au 圆盘电极相当的良好功能化和电化学活性。此外，他们证明这些三电极装置能够检测人体汗液中临床相关的葡萄糖浓度，这表明使用传统的大规模生产材料和设施制造可穿戴生物分子传感器的可能性，而无需进行复杂的修改。

Yoon 及其同事报告了一篇关于用于生物电子学的共轭聚合物设计原理的评论文章。^{[ 27 ]}他们回顾了对聚合物混合导体的基本理解、增强其离子和电导率的最新进展、长期材料/性能稳定性的限制，以及它们作为基于有机电化学晶体管的生物传感器的实际应用。特别是，详细讨论了混合电子/离子电导率中结构-性质关系及其相互作用的重要性。最后，提出了开发新型聚合物混合导体的关键策略，这些导体可能会超过器件性能和稳定性之间的权衡。

Inal 及其同事报告了掺杂剂和添加剂对电聚合共轭聚合物的电化学性能和操作稳定性的影响。^{[ 28 ]}基于 3,4-亚乙基二氧噻吩 (EDOT) 及其端羟基对应物 (EDOTOH) 的共聚物在各种抗衡阴离子和添加剂的存在下在水中进行电聚合。在开发的各种聚合物中，掺有 ClO ₄的共聚物 p(EDOT- ran- EDOTOH)在乙二醇存在下表现出较高的比电容和电化学稳定性。基于该聚合物的所得微电极阵列显示出适当的细胞活力、刺激/记录性能和设备操作稳定性，为了解掺杂剂和添加剂对电聚合共轭聚合物的电化学性能和设备稳定性的影响提供了见解。

本期特刊中的这十篇文章阐明了大分子生物电子学研究领域的最新技术和未来前景。深入了解它们的独特特性和可行性生物电子设备的可行性，将使设计适用于更复杂应用的新型聚合物材料取得突破。此外，在设计新型器件架构、保证操作稳定性、可扩展加工性和节省成本的制造技术方面的持续研究工作对于实现大分子生物电子学的早期商业化至关重要。最后，