Fabrication of high-performance microfluidic SERS substrates by metal-assisted chemical etching of silicon scratches. (1st September 2022)

• Record Type: Journal Article
• Authors: Peng, Yong; Cui, Licong; Gao, Jian; Jiang, Shulan; Wang, Hongbo; Yu, Bingjun; Qian, Linmao
• Is Part Of: Surface topography. Volume 10:Number 3(2022)
• Publication Date: 2022-09-01
• Subjects: SERS substrate -- metal-assisted chemical etching -- micro-nano nested structures -- nanomolar detection limits; Surfaces (Physics) -- Periodicals; Surfaces (Physics) -- Measurement -- Periodicals; 530.417
• DOI: 10.1088/2051-672X/ac81dd
• Languages: English
• ISSNs: 2051-672X

Abstract

Abstract: Surface-enhanced Raman spectroscopy (SERS) substrate-based microfluidic systems are applied extensively in diverse fields. For affordable detection and diagnosis, we propose a novel strategy for flexible, low-cost, and rapid fabrication of microfluidic SERS substrates by metal-assisted chemical etching of scratches on a silicon surface. A silicon substrate was spin-coated with polyketone resin (PK), and patterned by scratching with a diamond tip. Notably, defects created by diamond tip scratching on silicon substrate promoted subsequent metal deposition. A micro/nano nested structure was prepared by metal-assisted chemical etching process based on combined effect of scratching and metal catalysis. The PK layer served as a stable mask during metal deposition and etching. The prepared SERS-active detection sites with micro/nano nested structures exhibited substantial enhancement effects and good stability. Taking rhodamine 6G as a probe molecule, the microfluidic SERS substrate exhibited a high detection capability, with nanomolar detection limits (10 −9 M) and high long-term stability (at least 120 days). The micro/nano nested structure exhibited an enhancement factor of 2.725 × 10 5 compared to a gold film deposited on a flat silicon surface. The proposed method is promising for chemical and biological detection applications.