“…8,38,40,48,80 It could be explained by electromagnetic and chemical mechanisms, whereas electromagnetic SERS enhancement has been the most effective and highly acceptable. 38,40,42,48,80 The electromagnetic SERS mechanism is mainly due to the LSPR of noble metals, which shows a high EF due to their ease of fabrication and biocompatibility; however, there are some drawbacks when used as sole nanostructured materials in the form of powder or solutions. 79,81 Recent developments demonstrate that surface nanoengineering of noble metal-based SERS active substrates and their composites with semiconductors provide better morphology with 'hot spot' nanoarchitectures that are suitable for higher Raman signals due to the synergetic effect of electromagnetic and chemical enhancement.…”