Rapid and Sensitive Detection of Pentachloronitrobenzene by Surface-Enhanced Raman Spectroscopy Combined with Molecularly Imprinted Polymers

Abstract

Molecularly imprinted polymers (MIPs) specifically targeting pentachloronitrobenzene (PCNB) and containing silver nanoparticles have been prepared by free radical polymerization reaction using methyl methacrylate (MMA) as a functional monomer, PCNB as a template molecule, 1,4-butanedioldimethacrylate as a cross linker, lauroyl peroxide (LPO) as an initiator, and the silver nanoparticles with the best surface-enhanced Raman scattering (SERS) effect as SERS enhancement materials. Our results indicated that MIPs specifically recognize PCNB from complex matrices. The intensity of the PCNB characteristic peak was proportional to the concentration, with a linear range of 0.005 to 0.15 μg/mL and a limit of detection of 5.0 ng/mL. The recovery rates and relative standard deviation for the detection of PCNB spiked in the rice samples were from 94.4% to 103.3% and from 4.6% to 7.4%, respectively. The experimental results are consistent with those by the GC-MS method, indicating that the rapid detection of PCNB in food matrices by SERS-MIPs is reliable. In view of the insolubility of PCNB in water, oil-soluble silver nanoparticles were synthesized which can be expanded to detect oil-soluble toxic substances. For the first time, the proposed method provides a point-of-care and cost-effective tool for rapidly detecting PCNB in food matrices with high sensitivity and selectivity by employing SERS-MIPs method.

Molecularly Imprinted Plasmonic Sensors as Nano-Transducers: An Effective Approach for Environmental Monitoring Applications

“…Some optical transduction schemes based on SPR and fluorescence of nanocomposite MIP sensors and their applications in the analytical detection of Sudan dyes and paraquat in environmental samples have been highlighted (Figure 6). (A,B) illustrate the surface-enhanced Raman spectroscopy spectra interactions of 1 ppm of Pentachloronitrobenzene (PCNB) with oil-soluble silver-MIP [89]. Insert (C) also shows a schematic of a fluorescent silicon dioxide cadmium tellurium quantum dots (SiO2@CdTe QDs) MIP for the detection of paraquat in water samples.…”

Molecularly Imprinting–Aptamer Techniques and Their Applications in Molecular Recognition

“…In general, the preparation of MIPs requires the single-template imprints of targeted molecules or similar molecules that can bind to the functional groups of functional monomers through covalent or noncovalent molecular interactions. Template molecules can be removed from prepared polymers, leaving imprinted 3D skeleton cavities for the specific rebinding of target molecules [ 10 , 11 ]. The ability of MIPs to recognize targeted analyte molecules is influenced by many factors, including ionic strength, pH, solution polarity and polymer type and size [ 12 ].…”

Development of a Sensitive Ratiometric Imprinted Hydrogel for the Detection of Matrix Metalloproteinase 7 (MMP7) Biomarker

“…In line with this, point-of-care tests (PoCTs) focus on the quantification of several biological targets in a user-friendly perspective, taking advantage of the accuracy of the biorecognition method and the sensitivity of the corresponding technique. − In this context, molecularly imprinted polymers (MIPs) arise as new biomimetic recognition units to simulate the antigen antibodies interactions, already being used in the quantification of several biological targets with the advantage that can be adapted to PoCTs. − These three-dimensional structures are based on polymeric imprinting that mimics the structure and conformation of the target, thus acting as its biomimetic recognition element. MIPs possess higher chemical stability at wider pH ranges and temperatures, comparatively to immuno-based recognition methods and usually prepared with controlled size polymerization in aqueous media for the imprinting of large biomolecules as proteins. − Surface imprinting using free radical polymerization (FRP) techniques is one possible strategy for the assembly of MIPs around biological molecules, as it requires soft polymerization conditions in aqueous media. − Quantum dots (QDs) are semiconducting nanocrystals that find application as optical sensing probes. Its widespread use has been documented in the detection of MMP7 in immunoassays. , However, to the best of our knowledge, the conjugation of MIPs to QDs for the detection of MMP7 protein cancer biomarker by fluorescence spectroscopy has not been reported.…”