Integrating molecular imprinting and Fe-based MOF peroxide-like nanozyme for highly sensitive and selective detection of diethylstilbestrol

The development of simple, efficient and low-cost methods for rapid on-site monitoring have always been a challenging topic in the field of analysis. Here, we successfully constructed a selective, sensitive and rapid colorimetric sensor for the sensing of diethylstilbestrol (DES) by using molecular imprinting technology to construct specific recognition sites on the surface of Fe-based metal organic frameworks (Fe-MOF) peroxidaselike nanozyme. The surface of obtained sensor (Fe-MOF@MIP) had abundant channels and imprinted cavities that allowed the substrate to enter and responded with Fe-MOF core to drive the chromogenic reaction of 3,3 ',5,5 '-tetramethylbenzidine (TMB). When DES was present, it could specifically enter the cavities and obstruct the channels of substrate into the Fe-MOF core, thereby inhibiting the chromogenic reaction. The experimental results demonstrate that the sensor had excellent selectivity, anti-interference and catalytic stability. In the linear range of 0 - 1.67 mu M, the detection limit is as low as 8.43 nM, which is superior to peer sensors. To better adapt to in-situ analysis, we have further developed a rapid analysis method based on photo colorimetry, which performed well in real sample analysis and recovery test with the results consistent with the gas chromatographmass spectrometer (GC-MS), demonstrating its great potential for rapid on-site monitoring.