Ultra-High-Throughput Discovery of Multifunctional Polyphenolic Coatings on Droplet Microarrays

The rapid discovery of new functional coatings is vital for advancing technologies in healthcare, energy, and environmental protection. These surface materials define how objects interact with their surroundings, enabling antibacterial, antifouling, catalytic, or cell-adhesive functions, yet their development remains slow due to the lack of scalable, high-throughput methods for synthesis and screening of different coatings. Here, we introduce an ultra-high-throughput (UHT) combinatorial strategy for the miniaturized discovery of multifunctional coatings based on polyamine-polyphenol chemistry, a versatile and naturally inspired reaction motif. Polyphenols—over 8,000 identified to date—possess rich redox, optical, and biological activities, but their vast combinatorial potential remains largely untapped.
Using the droplet microarray (DMA) platform, we synthesized and screened ≈30,000 polyamine–polyphenolic (PaPp) coatings formed from binary and ternary combinations of 51 polyphenols and 12 polyamines, each produced in 160 nL volumes (<5 mL total reagent use). This ultra-high-throughput workflow enabled the rapid identification of hundreds of previously unknown fluorescent coatings, including over 225 strong green-, blue-, or red-emissive PaPp materials. Systematic redox screening revealed more than 100 highly active metal-reducing coatings, dominated by PaPp combinations containing galloylated or catecholic structures, with the ternary compositions Pa2Pp43Pp44 and Pa2Pp43Pp45 emerging as the strongest reducers.
Antibacterial screening uncovered seven PaPp coatings with reproducible activity against Pseudomonas aeruginosa, and subsequent validation on macroscale substrates confirmed up to <1 log CFU reduction against P. aeruginosa and E. coli. Importantly, five coatings exhibited multiple functionalities, including Pa2Pp3, Pa2Pp6, Pa6Pp3, Pa8Pp18, and Pa9Pp18, which combined surface stability, intrinsic fluorescence, metal-reducing activity, antibacterial effects, and compatibility with adherent human cells. Several additional coatings were identified as fluorescent–redox dual-functional materials (e.g., Pa2Pp7, Pa6Pp33, Pa8Pp9, etc.), or redox-active but cell-compatible surfaces, expanding the design space for optically traceable, redox-responsive, or bioactive interfaces.
Together, this UHT approach yields the first comprehensive functionality map of polyamine–polyphenolic coatings, revealing previously inaccessible multifunctional materials and demonstrating a scalable strategy for the discovery of surface chemistries with tailored optical, redox, and biological properties.

新型功能涂层的快速发现对于推动医疗健康、能源与环境保护领域的技术进步至关重要。这类表面材料决定了物体与周围环境的相互作用方式，可实现抗菌、防污、催化或细胞黏附等功能，但其开发进程仍较为缓慢，原因在于缺乏可规模化、高通量的合成与筛选不同涂层的方法。在此，我们提出一种基于聚胺-多酚化学（polyamine-polyphenol chemistry）的超高通量（ultra-high-throughput, UHT）组合策略，用于小型化发现多功能涂层——该反应基元具有多功能性且灵感源于自然。多酚类物质——目前已鉴定出8000余种——拥有丰富的氧化还原、光学与生物活性，但其巨大的组合潜力尚未得到充分开发。
借助液滴微阵列（droplet microarray, DMA）平台，我们合成并筛选了约30000种聚胺-多酚（polyamine–polyphenolic, PaPp）涂层，这些涂层由51种多酚与12种聚胺的二元、三元组合构成，每种涂层的制备体积为160纳升，总试剂消耗量小于5毫升。该超高通量工作流程可快速鉴定出数百种此前未知的荧光涂层，其中包括225余种具有强绿色、蓝色或红色发光特性的PaPp材料。系统性氧化还原筛选发现了100余种高活性金属还原涂层，这类涂层主要由带有没食子酰基或儿茶酚结构的PaPp组合构成，其中三元组合物Pa2Pp43Pp44与Pa2Pp43Pp45表现出最强的还原能力。
抗菌筛选发现了7种对铜绿假单胞菌（Pseudomonas aeruginosa）具有可重复抗菌活性的PaPp涂层，随后在宏观基底上的验证实验证实，这些涂层可使铜绿假单胞菌与大肠杆菌（E. coli）的菌落形成单位（CFU）数量降低至多1个对数级。值得注意的是，有5种涂层展现出多种功能特性，包括Pa2Pp3、Pa2Pp6、Pa6Pp3、Pa8Pp18与Pa9Pp18，它们兼具表面稳定性、本征荧光性、金属还原活性、抗菌效果以及与人类贴壁细胞的相容性。另有多种涂层被鉴定为荧光-氧化还原双功能材料（如Pa2Pp7、Pa6Pp33、Pa8Pp9等），或是具有氧化还原活性且与细胞相容的表面，拓展了可光学追踪、氧化还原响应或生物活性界面的设计空间。
综上，该超高通量方法首次绘制了聚胺-多酚涂层的全面功能图谱，揭示了此前难以获取的多功能材料，并证明了一种可规模化的策略，用于开发具有定制化光学、氧化还原与生物学特性的表面化学体系。