Fabrication of black phosphorous quantum dots and Ag nanoparticles co-sensitized TiO2 nanorod arrays as powerful SERS substrate

Surface enhanced Raman scattering (SERS) substrate based on plasma metal nanoparticles and non-metal quantum dots co-sensitized semiconductor has been used in limit trace detection test. In this research, BPQDs (black phosphorus quantum dots) and Ag nanoparticles co-sensitized TiO2 nanorod arrays were successfully fabricated as powerful SERS substrate. For BPQDs/Ag/TiO2, its detection limit of 4-mercaptobenzoic acid (4-MBA) molecules could achieve even at as low as 1.0 x 10(-12 )M, and the enhancement factor (EF) is up to 2.5 x 10(5), exhibiting an excellent SERS sensitivity. Furthermore, a good uniformity is also observed during the detection process, the relative standard deviation of 4-MBA Raman fingerprint peak intensity at 1587 cm(-1) is only 7.3 %. Furthermore, BPQDs/Ag/TiO(2 )substrate is demonstrated to have good repeatability and stability. The synergistic effect of BPQDs, Ag nanoparticles and TiO2 nanorod array is mainly responsible for improved SERS activity, namely, high-density hot spot, optical capture expansion and enhanced charge transfer. (C) 2022 Published by Elsevier B.V.

Automated summary

A SERS substrate based on black phosphorus quantum dots (BPQDs) and silver nanoparticles co-sensitized titanium dioxide nanorod arrays has been successfully fabricated for limit trace detection test. The substrate shows high sensitivity, good uniformity, and excellent repeatability and stability, making it a promising candidate for SERS applications. The improved SERS activity is attributed to the synergistic effect of BPQDs, silver nanoparticles, and titanium dioxide nanorod arrays.