Gold‐patterned microarray chips for ultrasensitive surface‐enhanced Raman scattering detection of ultratrace samples

Abstract

This paper reports the fabrication of gold‐patterned microarray chips for fast and ultrasensitive surface enhanced Raman scattering (SERS) detection of trace samples. By micro‐nano machining based on electron‐beam lithography, magnetron sputtering, and chemical modification, gold‐patterned microarray chips with hydrophilic and hydrophobic periodic structures are fabricated, and a polyethylene glycol (PEG) layer is coated on the surface of the gold well, making the chips long‐term stable. The hydrophilic surface of each gold well is surrounded by a hydrophobic layer, which makes the ultratrace sample amount for SERS measurement only 0.3 μl. In the detection of malachite green (MG), 4‐mercaptopyridine (4‐MPY), rhodamine 6G (R6G), and melamine, great enhanced SERS signals with the detection limit reaching nM level can be achieved due to the enrichment effect of the periodic structures and the hot‐spots generated between the sandwich structure built on the gold wells. Such gold‐patterned microarray chip is promising in fast and ultrasensitive SERS detection of various chemical and biological species with trace amount.

Recent advances in linear and nonlinear Raman spectroscopy. Part XIV

“…Their results indicate that the 4‐methylthiophenol‐ and thiophenol‐modified substrates do not exhibit significant SERS enhancement, resulting in intensity being dependent on distance. Chen et al [ 17 ] reported the fabrication of gold‐patterned microarray chips for fast ultrasensitive SERS detection of trace samples. They conclude that such gold‐patterned microarray chips are promising for SERS detection of various chemical and biological species, such as only 0.3 μl in the detection of malachite green, 4‐mercaptopyridine, rhodamine 6G, and melamine, with the detection limits reaching the nm.…”

Uniform Near-Spherical Nanoscale Silver Films for Surface-Enhanced Raman Spectroscopy Sensing

“…Surface-enhanced Raman scattering (SERS), as a rapid response, high sensitivity, and fingerprint effect spectroscopy technique, has been most intensively exploited in many areas of the trace detection of analytes, biological analysis, medical detection, and other molecule level identification applications. − At present, the more widely used surface-enhanced Raman substrates are noble-metal colloids due to their superior surface-enhanced Raman performances. − Unfortunately, as for them, there are also various disadvantages such as harsh preparation conditions, residual surfactant or surface protective reagent interference, and easy aggregation during use and storage. , Gradually, some physical methods like electron-beam lithography, focused ion-beam lithography, photolithography, and so on have been developed to overcome the shortcomings of the colloidal chemistry methods. − These methods can produce nanostructures with precise size, regular shape, and uniform hot spot distribution. However, such methods suffer from small sample volume, high cost, and complex instrumentation, which are very unfavorable for the future practical application of the substrates.…”