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 (Cu2O@SiO2@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 Cu2O@SiO2@ZIF-8 favored the AgNPs to be uniformly distributed in the Cu2O@SiO2@ZIF-8. When more AgNPs were obtained in the cavity of Cu2O@SiO2@ZIF-8 with large surface areas (-568.95 m2/g), higher SERS response towards phenol red was resulted in. Moreover, 4 nm AgNPs embedded Cu2O@SiO2@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 Cu2O@SiO2@ZIF-8@Ag changed little within 35 days, and also the low concentration of phenol red in actual sample can be detected. Therefore, the Cu2O@SiO2@ZIF-8@Ag could be employed as highly sensitive and continuously stable 3D substrate for SERS detection of environmental contaminants.