Large‐Area Gold‐Coated Polyamide Nanopillar Arrays Consisting of Secondary Lamellar Structures and Sub‐10‐nm Gaps for Ultrasensitive SERS Detection

Abstract

Large‐area gold‐coated polyamide 66 (PA66) nanopillar (PA66NP@Au) arrays consisting of secondary lamellar structures and sub‐10–nm gaps are fabricated for surface‐enhanced Raman spectroscopy (SERS) using ultrathin anodized aluminum oxide (AAO) template, solution‐phase growth of PA66 lamellae, and Au sputtering. Such closely packed PA66NP@Au arrays with high density of electromagnetic field enhancement (“hot spots”) on large area exhibit high SERS sensitivity for detection of rhodamine 6g (R6G) molecules with concentration down to 10−14 m and a large Raman analytical enhancement factor (AEF) of ≈1010. Furthermore, the as‐fabricated PA66NP@Au arrays provide highly sensitive Raman signals in detection of a commonly pesticide residue, carbendazim with a limit of detection (LOD) of 0.05 mg L−1 (0.05 ppm), which is lower than that of maximum residue limit of 0.2 ppm allowed in Europe Union. The as‐fabricated PA66NP@Au arrays are promising for highly sensitive and uniform SERS detection.

Development of two-photon polymerized periodic nanostructures for label-free SERS biosensing

“…Lin et al fabricated a nanopillar array by casting polyamide 66 in a 150 nm thick anodized aluminum oxide template. By growing secondary structures on the pillars and coating them with gold, they achieved sub-10 nm gaps for which they reported a 10 -14 M R6G LOD [12]. Similar to these examples, much SERS fabrication research has focused on random processes, such as using naturally existing nanostructures, roughening surfaces, and self-assembly.…”