Ultrasensitive Detection of Malachite Green Isothiocyanate Using Nanoporous Gold as SERS Substrate

In this article, a high-performance nanostructured substrate has been fabricated for the ultrasensitive detection of the organic pollutant, Malachite green isothiocyanate (MGITC), in aquatic systems via the Surface Enhanced Raman Spectroscopy (SERS) technique. The chemical dealloying approach has been used to synthesize a three-dimensional nanoporous gold substrate (NPG) consisting of pores and multigrained ligament structures along thickness. The formation of the framework in NPG-5h has been confirmed by SEM with an average ligament size of 65 nm at the narrower neck. Remarkable SERS performance has been achieved by utilizing the NPG-5h substrate for the detection of MGITC, showing a signal enhancement of 7.9 x 10(9). The SERS substrate also demonstrated an impressively low-detection limit of 10(-16) M. The presence of numerous active sites, as well as plasmonic hotspots on the nanoporous surface, can be accredited to the signal amplification via the Localized Surface Plasmon Resonance (LSPR) phenomenon. As a result, SERS detection technology with the fabricated-NPG substrate not only proves to be a simple and effective approach for detecting malachite green but also provides a basis for in situ detection approach of toxic chemicals in aquatic ecosystems.

Automated summary

In this article, a high-performance nanostructured substrate has been developed for the ultrasensitive detection of a specific organic pollutant, Malachite green isothiocyanate (MGITC), in aquatic systems. The substrate, called nanoporous gold (NPG), was synthesized using a chemical dealloying approach and exhibited remarkable surface enhanced Raman spectroscopy (SERS) performance with a signal enhancement of 7.9 x 10(9) and a low detection limit of 10(-16) M. The signal amplification was attributed to the presence of numerous active sites and plasmonic hotspots on the nanoporous surface, resulting from the localized surface plasmon resonance (LSPR) phenomenon. This technology not only provides a simple and effective approach for detecting malachite green but also lays the foundation for in situ detection of toxic chemicals in aquatic ecosystems.