Molecularly imprinted sensors based on highly stretchable electrospun membranes for cortisol detection

[Display omitted] •A flexible MIP cortisol electrochemical sensor based on MXene/CNTs composites was prepared for the detection of cortisol in sweat.•The M1C2 based electrochemical sensor had a linear detection range of 0.417 nM-1.28 μM, with high specificity and selectivity.•This work provided a new strategy for detecting cortisol in sweat, enabling real-time monitoring of cortisol. Cortisol is a stress-sensitive glucocorticoid that is a key indicator of the body’s physical and mental health. However, current detection methods often suffer from issues such as high cost, complexity, and inability to monitor in real time. Combining molecular imprinting (MIP) technology with flexible substrate preparation technology to prepare wearable sensors on fiber membranes is a feasible solution for achieving low-cost, fast, and real-time monitoring. In this article, we integrated a flexible wearable MIP sensor on the TPU fiber membrane prepared by an electrospinning method for monitoring cortisol molecules. Then the composite material of MXene nanosheets and Carbon nanotubes (CNTs) is assembled onto a fiber membrane by spraying to form a working electrode. The three-dimensional interconnected conductive network, high specific surface area, and high conductivity significantly improve the sensing performance of electrodes, and the linear detection range of the MIP cortisol electrochemical sensor can reach 0.417 nM-1.28 μM. It is also effective in distinguishing cortisol from other interfering substances. TPU fiber membranes can be combined with fabrics, thus providing a material basis for the realization of portable, wearable, and fast-detecting cortisol sensors.