Ultra sensitive surface‐enhanced Raman scattering detection based on monolithic column as a new type substrate

Abstract

A novel ultrasensitive detection method utilizing surface-enhanced Raman scattering (SERS) based on monolithic column was developed in the present study. Monolithic column is a kind of chromatographic stationary phase that contains highly interconnected pores and absorbs chemical components efficiently. Dropping a mixture solution containing analyte, silver colloid, and NaCl on the surface in advance, SERS signals were collected on the surface of the monolithic column. With this method, five commonly used probe molecules of Rhodamine 6G (R6G), p-aminothiophenol, Rhodamine 123, crystal violet, thymine, and two chemicals that are used in agriculture (paraquat and flusilazole) were detected. Especially, R6G and p-aminothiophenol can be detected at extremely low concentrations of 10 -18 and 10 -16 mol/L at milliliter level, respectively. The enhancement factor was calculated to be approximately 10 14 for R6G detection. The results suggest that the monolithic column does improve the sensitivity of SERS detection dramatically and the topography of the monolithic column is essential for the enhancement. The easy operability and the significant enhancement are the greatest advantages of this method.

Towards attomolar detection using a surface-enhanced Raman spectroscopy platform fabricated by nanosphere lithography

“…Shao et al reported a LOD of 10 −16 mol/L, with a volume of 25 L, yielding a total of 1.5 × 10 3 molecules, whereas Li et al reported the detection of a similar number of molecules using 2 mL of a 10 −18 mol/L solution of R6G. 36,37 The work by Li et al also reported a LOD of 60 molecules obtained with 10 −18 mol/L and with only 100 L of the solution. 38 Since the detected molecules are adsorbed onto the surface of the platform, it is possible to determine the LOD with respect to the number of molecules within the probed area.…”

“…For rhodamine 6G (R6G), LODs of between 10 −10 and 10 −18 mol/L have been reported. [33][34][35][36][37][38] The limitation of solely using the concentration is that it does not refer to the actual number of molecules that can potentially adsorb to the surface of the platform. Shao et al reported a LOD of 10 −16 mol/L, with a volume of 25 L, yielding a total of 1.5 × 10 3 molecules, whereas Li et al reported the detection of a similar number of molecules using 2 mL of a 10 −18 mol/L solution of R6G.…”

A new SERS substrate based on silver nanoparticle functionalized polymethacrylate monoliths in a capillary, and it application to the trace determination of pesticides

“…[16][17][18][19]. Typically, as the traditional stationary phases in separation science, the monolithic columns have micrometer-to nanometer-sized interconnected fluidic channel networks which support convection flow for rapid mass transfer.…”

“…Simultaneously, it offers short characteristic diffusion lengths and large surface areas for enhanced analyte-monolith interactions. In the previous work [17,20], the monolithic columns were employed as SERS scaffold to offer binding sites for metal nanoparticles, and the silver or gold nanoparticles were assembled onto the columns surface to achieve ultrasensitive SERS detection. Although these substrates exhibit remarkable SERS performance, some tough issues still need to be improved, such as uniformity and reproducibility.…”

On-column enrichment and surface-enhanced Raman scattering detection in nanoparticles functionalized porous capillary monolith

“…Moreover, porous polymer monolithic materials with a large surface area are also used as SERS matrixs to trap analytes for chemical and biological sensing. The Au (or Ag) nanostructures could be either embedded in polymer monolithic materials or dropped onto their surfaces to trap analytes for ultrasensitive detections [18][19][20].…”