Dendrimer‐Based Gold Nanostructures for SERS Detection of Pesticides in Water

Abstract

Dendrimers are polymers with well‐defined architectures and tunable chemistry, which make them useful in a number of applications. Herein, the chemistry of poly(amido)amine (PAMAM) dendrimers with different functional groups was explored to produce a variety of plasmonic systems based on Au colloidal nanoparticles. The resulting systems present long‐term colloidal stability and were investigated as sensitive platforms for surface‐enhanced Raman scattering (SERS). The application of these SERS platforms for the detection of water trace pollutants, was explored through the analysis of selected pesticides. Noteworthy, dendrimer coated Au nanoparticles with tunable properties such as size, shape and surface chemistry, were obtained by varying the dendrimer chemical properties. The surface chemistry of PAMAM capped Au colloids was explored in order to produce target selective SERS substrates for pesticide detection, that allowed to reach detection limits down to 10 nm.

Colloidal dendritic nanostructures of gold and silver for SERS analysis of water pollutants

“…The Au, Ag and alloy dendrimer-stabilized nanoassemblies were prepared according to previously reported procedures with several adaptations [47][48][49]. In this work, the particles were obtained using the 5 th generation PAMAM dendrimer with primary amine terminal groups as a reducing and stabilizing agent.…”

“…SERS has proved to be an alternative analytical technique for the trace detection of analytes in aqueous samples, given its easy implementation and high sensitivity. In previous work, we have demonstrated the potential of dendrimer-based gold systems for the SERS detection of chemical pesticides under variable operational conditions [47]. Herein, binary Ag:Au dendrimer-based assemblies have been investigated for the SERS detection of ziram and thiram in water samples.…”

Functionalized gold nanoparticles for sensing of pesticides: A review

“…In recent year, several pesticides such as omethoate [ 137 ], chlorpyrifos [ 137 ], acetamiprid [ 138 ], clothianidin [ 138 ], phosmet [ 138 ], thiram [ 138 ], paraquat [ 139 ], carbendazim [ 140 ], pyrimethanil [ 141 ] was determined by SERS with easy-to-prepare AuNPs as shown in Table 3 . Fernandes et al [ 142 ] used dendrimer stabilized anisotropic AuNPs as SERS probes for the detection of sodium diethyldithiocarbamate, thiram, and paraquat in water. Tan et al [ 143 ].…”

Nanoscale Surface-Enhanced Raman Spectroscopy Investigation of a Polyphenol-Based Plasmonic Nanovector

“…However, one of the main problems related to pharmaceutical applications of such composite systems is the lack of knowledge of the specific chemical composition of the nanomaterial surface, which indeed mainly determines its interacting properties and, if not properly controlled, guide to side-effects and non-desired behaviors of the system. By exploiting the significant signal enhancement (typically, 6-8 orders of magnitude) due to the localized surface plasmon resonance (LSPR) of noble metal nanostructures and the molecular specificity of Raman spectroscopy, Surface-Enhanced Raman Scattering (SERS) spectroscopy can be an extraordinary tool to access the real chemical state of molecules in the proximity of metal NPs, thus providing important information on the surface chemical properties of the system [ 31 , 32 ]. In the perspective of exploiting polyphenol-AgNPs as new multifunctional nanovectors, the use of an ultrasensitive and molecular-specific probe can be crucial for a thorough investigation of the system beyond the extent of conventional analytical methods.…”