SERS and SEF with enhancement in nanogaps: from fabrication to biosensing

. However, unstructured nanofabrication techniques like self-assembly have a more affordable price, lower complexity, and better scalability. Therefore, SA can easily compete with ordered nanofabrication techniques. In addition, this review also highlights the applications of nanogaps in label-free detection and biomarker detection. Finally, this review highlights applications of nanogap enhancement in SEF and draws conclusions on the current state of nanogap research and its future.