A special zinc metal-organic frameworks-controlled composite nanosensor for highly sensitive and stable SERS detection

Using 5-mercapto-1-methyltetrazole as the bridge, a porous (~4 nm) Zn metal–organic frameworks coated cuprous oxide/silica core–shell nanostructure (Cu2[email protected]2@ZIF-8) was facilely fabricated. Subsequently, using it as a template, the precisely controlled growth of AgNPs with various sizes (2 nm~29 nm) was achieved. It was found that a strong interaction between AgNPs and ZIF-8 in the Cu2[email protected]2@ZIF-8 favored the AgNPs to be uniformly distributed in the Cu2[email protected]2@ZIF-8. When more AgNPs were obtained in the cavity of Cu2[email protected]2@ZIF-8 with large surface areas (~568.95 m2/g), higher SERS response towards phenol red was resulted in. Moreover, 4 nm AgNPs embedded Cu2[email protected]2@ZIF-8 substrate showed a lower limit of detection (5.76 × 10-12 mol·L-1) and limit of quantification (1.92 × 10-12 mol·L-1), and a higher enhancement factor of 1.7 × 107. Additionally, Raman activity of the Cu2[email protected]2@[email protected] changed little within 35 days, and also the low concentration of phenol red in actual sample can be detected. Therefore, the Cu2[email protected]2@Z[email protected] could be employed as highly sensitive and continuously stable 3D substrate for SERS detection of environmental contaminants.