Department of Biomedical Engineering, Tianjin University, 92 Weijin Road, Tianjin, 300072, China.
Department of Mechatronics and Biomedical Engineering, Universiti Tunku Abdul Rahman, Cheras, 43000, Kajang, Selangor, Malaysia.
Adv Mater. 2018 Jun;30(23):e1800917. doi: 10.1002/adma.201800917. Epub 2018 Apr 6.
The combination of novel materials with flexible electronic technology may yield new concepts of flexible electronic devices that effectively detect various biological chemicals to facilitate understanding of biological processes and conduct health monitoring. This paper demonstrates single- or multichannel implantable flexible sensors that are surface modified with conductive metal-organic frameworks (MOFs) such as copper-MOF and cobalt-MOF with large surface area, high porosity, and tunable catalysis capability. The sensors can monitor important nutriments such as ascorbicacid, glycine, l-tryptophan (l-Trp), and glucose with detection resolutions of 14.97, 0.71, 4.14, and 54.60 × 10 m, respectively. In addition, they offer sensing capability even under extreme deformation and complex surrounding environment with continuous monitoring capability for 20 d due to minimized use of biological active chemicals. Experiments using live cells and animals indicate that the MOF-modified sensors are biologically safe to cells, and can detect l-Trp in blood and interstitial fluid. This work represents the first effort in integrating MOFs with flexible sensors to achieve highly specific and sensitive implantable electrochemical detection and may inspire appearance of more flexible electronic devices with enhanced capability in sensing, energy storage, and catalysis using various properties of MOFs.
新型材料与柔性电子技术的结合可能产生新型的柔性电子设备概念，这些设备可以有效地检测各种生物化学物质，从而有助于理解生物过程并进行健康监测。本文展示了具有单通道或多通道的可植入柔性传感器，这些传感器的表面经过修饰，使用了具有大表面积、高孔隙率和可调催化性能的导电金属-有机骨架（MOF），如铜-MOF 和钴-MOF。这些传感器可以监测重要的营养物质，如抗坏血酸、甘氨酸、l-色氨酸（l-Trp）和葡萄糖，检测分辨率分别为 14.97、0.71、4.14 和 54.60×10^-6 mol/L。此外，由于生物活性化学物质的使用量减少，它们即使在极端变形和复杂的周围环境下也具有传感能力，并且能够持续监测 20 天。使用活细胞和动物的实验表明，修饰后的 MOF 传感器对细胞是生物安全的，并且可以检测血液和间质液中的 l-Trp。这项工作代表了首次将 MOF 与柔性传感器集成，以实现高度特异性和灵敏的可植入电化学检测的努力，并且可能会激发更多具有增强的传感、储能和催化能力的柔性电子设备的出现，这些设备可以利用 MOF 的各种特性。
