Author(s): Lyu, S (Lyu, Shuangbao); Zhang, YL (Zhang, Yongliang); Du, GH (Du, Guanghua); Di, CX (Di, Cuixia); Yao, HJ (Yao, Huijun); Fan, YL (Fan, Yulong); Duan, JL (Duan, Jinglai); Lei, DY (Lei, Dangyuan)

Source: SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY Volume: 285 Article Number: 121801 DOI: 10.1016/j.saa.2022.121801 Published: JAN 15 2023

Abstract: Porous membrane-based nanofiltration separation of small biomolecules is a widely used biotechnology for which size-based selectivity is a critical parameter of technological relevance. Efficient determination of size selectivity calls for an advanced detection method capable of performing sensitive, rapid, and on-membrane examination. Surface-enhanced Raman spectroscopy (SERS) is such a detection method that has been widely recognized as an ultrasensitive technique for trace-level detection with sensitivity down to the single-molecule level. In this work, we for the first time develop a double-sided hierarchical porous membrane-like plasmonic metasurface to realize high-selectivity bimolecular separation and simultaneous ultrasensitive SERS detection. This highly flexible device, consisting of subwavelength nanocone pairs surrounded by randomly orientated sub -5 nm nanogrooves, was prepared by combining customized "top-down" fabrication of conical nanopores in anion-track registered polycarbonate membrane and self-assembly of nanogrooves on the membrane surface through physical vapor deposition. The unique tip-to-tip oriented conical nanopores in the device enables excellent size-based molecular selectivity; the hierarchical groove-pore structure supports a peculiar cascaded electromagnetic near-field enhancement mechanism, endowing the device with SERS-based molecular detection of ultrahigh sensitivity, uniformity, repeatability, and polarization independence. With such dual structural merits and performance enhancement, we demonstrate effective nanofiltration separation of small-sized adenine from big-sized ss-DNA and synergistic SERS determination of their species. We experimentally demonstrate an ultrasensitive detection of 4-mercaptopyridine down to 10 pM. Together with its unparalleled mechanical flexibility, this double-side-responsive plasmonic metasurface membrane can find great potential in real-world molecular filtration and detection under extremely complex working conditions.

Accession Number: WOS:000860343500007

PubMed ID: 36122462

ISSN: 1386-1425

eISSN: 1873-3557

Full Text: https://www.sciencedirect.com/science/article/pii/S1386142522009490?via%3Dihub