Al plate supported MXene films modified with Ag nanoparticles: Highly sensitive and disposable SERS substrate for trace catechol in seawater

In this study, MXene films with an ordered layered structure were fabricated on Al plates via electrodeposition. Next, the Ag nanoparticles were modified on the MXene films through in situ reduction. Meanwhile, their surface enhanced Raman scattering effect for trace catechol was directly explored in catechol aqueous solution. It was found that these MXene films possess very strong surface enhanced Raman scattering effect for trace catechol in water. The detection limit is up to 5 × 10−8 mol L−1. In addition, these films possess high selectivity, excellent signal repeatability (relative standard deviation < 5.86%, spot-to-spot), high reproducibility (relative standard deviation < 5.86%, batch-to-batch) and good stability. More interestingly, the aforementioned films possess excellent salt tolerance and are highly sensitive to trace catechol in seawater. The detection limit is up to 1 × 10−7 mol L−1 in seawater. Moreover, there exists a good linear relationship between Raman signal intensity and catechol concentration within a broad concentration range of catechol (1 × 10−5 mol L−1 –1 × 10−7 mol L−1). These results imply that these MXene films possess great potential in timely monitoring of catechol in seawater. And its large-scale preparation and application might be simple and easy.