A smart MXene-copolymeric molecularly imprinted hydrogel with dual-response and photothermal conversion performance for specific recognition of cis-diol compounds

In this work, a novel MXene-copolymeric molecularly imprinted hydrogel (FMMIH) with temperature/pH dual response and photothermal conversion performance for selective recognition of cis-diol compounds is successfully prepared. Functionalized MXene becomes an important part of the hydrogel’s skeleton by participating in the free radical polymerization reaction. Therefore, FMMIH exhibits improved mechanical properties and great photothermal conversion performance. Furthermore, based on the temperature/pH dual response, FMMIH can realize the controllable capture and release of ginsenoside Rb1 with cis diol structures through dual recognitions of functional groups and geometric space. Under the conditions of pH 8.5 and 25 °C, the adsorption capacity of FMMIH is 26.3 mg·g^-1 and the imprinting factor is 16.4, showing a good imprinting effect. It is worth noting that the volume shrinkage caused by photothermal conversion of the hydrogel is conducive to the elution of template molecules and greatly saves the time of desorption (the desorption efficiency is as high as 89.4% under light conditions for 30 min, which is 3.7 times in dark conditions). These excellent properties make it possible to have broad prospects in many fields such as separation of cis-diol compounds, drug delivery systems, and biosensors.