Fabrication of a metal organic framework (MOF)‐modified Au nanoparticle array for sensitive and stable SERS sensing of paraquat in cereals

Abstract

A high‐performance Au@MIL‐101/PMMA/DT surface‐enhanced Raman scattering (SERS) substrate was fabricated for sensitive and stable detection of paraquat by self‐assembling metal organic framework–modified Au nanoparticles (Au@MIL‐101) on a poly(methyl methacrylate) (PMMA) film and then immobilizing the formed substrate onto a duct tape (DT). The highly closely packed Au@MIL‐101 array provided intensive hotspots for SERS sensing. The MIL‐101 layer modified on the surface of Au nanoparticles could absorb paraquat to the electromagnetic enhancement area of Au nanoparticles. The DT on the bottom made the substrate smoother, which is beneficial for achieving a more stable detection performance. As a result, the constructed substrate exhibited outstanding uniformity with relative standard deviations of 9.47% and storage stability for 2 months. For detecting paraquat, the substrate showed a low detection limit of 7.1 × 10−9 M (1.83 µg/kg) and wide linear range from 10−8 to 10−2 M. Furthermore, the substrate showed good detection performance in real cereal samples with desirable recovery rates from 91.57% to 102.32%.

Metalation of metal–organic frameworks: fundamentals and applications

“…MNPs with large surface area and good biocompatibility can be grafted to biosensors due to the ease of immobilization of biomolecules on supports. 298,301,313,320,323,422,423 So far, a large number of sensors based on MNPs@MOF composites have been reported, which have been widely used in electrochemiluminescence (ECL), 315,331 colorimetry, 299,324,352,424–427 surface-enhanced Raman scattering (SERS), 305,311,312,428–430 and others. 307,341,346,431–436…”

Design, Fabrication, and Applications of SERS Substrates for Food Safety Detection: Review

“…The design of SERS substrates should be tailored to the specific target substances. In food safety applications, the target substances can be categorized into two groups: small amount molecules [ 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ] and tiny biomaterials, such as cells [ 89 , 90 , 91 , 92 ], cell walls [ 93 , 94 , 95 , 96 ], and spores [ 97 , 98 , 99 , 100 ]. The key distinction between these two categories lies in their size.…”

“…The key distinction between these two categories lies in their size. Molecules are typically smaller than 100 nm and can be accommodated within the hotspot of the SERS substrate [ 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 ]. On the other hand, tiny biomaterials are generally larger than 100 nm and cannot fit into the small hotspot of the SERS substrate [ 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 ].…”

Plasmonic coupling of silver nanospheres loaded on cobalt–iron layered double hydroxides: a robust SERS probe for 4-nitrophenol detection

“…28 Electromagnetic enhancement was reported as the primary mechanism contributing to the SERS enhancement. 29 Strong local electric fields originate from intensely localized surface plasmon resonance (LSPR) in the plasmonic nanostructures called “plasmonic hotspots”. It can significantly increase the Raman signal intensities of analytes by electromagnetic enhancement.…”