Interfacial Engineering of Two-Dimensional Metal-Organic Framework Thin Films for Biomimetic Photoadaptative Sensors

Porphyrin-based two-dimensional metal-organic frameworks (2D MOFs) are of high interest for extraordinary optoelectronic devices due to their well-ordered architecture and appealing photochemical properties. However, the high-throughput synthesis of 2D MOF thin films for device applications remains challenging because of the slow nucleation and crystallization process in classical interfacial synthesis. Here, we report a microwave-assisted interfacial methodology for the rapid construction (∼3 min) of highly crystalline 2D MOF thin films and demonstrate their promising potential in biomimetic optical sensors. The resultant 2D MOF films exhibit a lateral size of up to ∼23 cm2 and controllable thickness in the range of 2-40 nm. The crystal domain size of the 2D MOF can be up to ∼4 μm, which boasts a long-range molecular ordering and appealing optical responsive properties. The 2D MOF films enable the fabrication of biomimetic optical sensors with light intensity-dependent autonomous photoadaptation without the assistance of voltage gating. Furthermore, an artificial machine vision system consisting of a 4 × 8 2D MOF-sensor array is developed to implement adaptive image recognition under bright- and dim-light stimuli with an accuracy of over 90%.