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.

The combination of metal‐organic frameworks (MOFs) and flexible electronics to yield a distributed biosensor is demonstrated by Hang Xu, and Xian Huang, and co‐workers in article number https://doi.org/10.1002/adma.201800917. A multichannel flexible device is integrated with nanosized MOFs to conduct highly specific electrochemical sensing of nutrients. Techniques and materials are revealed to monitor the distribution and transportation of nutrients and other biomolecules in multiple organ locations with high throughput, offering promising tools for understanding the mechanisms of symptoms related to nutrient deficiency, metabolism disorder, and neurological disease.