Au Sputtered Paper Chromatography Tandem Raman Platform for Sensitive Detection of Heavy Metal Ions

Abstract

Surface-enhanced Raman scattering (SERS) is a powerful technique for sensitive detection, but it normally has difficulty in multicomponent detection in a complex system, especially for simultaneous analysis of mixture of heavy metal ions. In this work, a simple paper chromatography tandem SERS (PC-SERS) separation/detection platform is proposed by ion-sputtering gold on a filter paper. Based on SEM results, the great electromagnetic field inside nanogaps of Au nanoislands on the paper surface is evaluated with FDTD simulation. It is found that the PC-SERS platform has good uniformity (RSD = 10.12%) and long-time stability. The as-prepared PC-SERS platform was applied to efficiently separate and detect a mixture of pesticides (MG, MB, and CV) in pond water without any pretreatment process, and the limits of detection (LODs) were down to 10 nM. As a crucial application for food safety, several heavy metal ions such as Cd 2+ , Cu 2+ , and Ni 2+ in grinded rice were successfully detected by the PC-SERS method taking advantage of the sandwich structure based on 4-mercaptobenzoic acid (4-MBA) molecules, which were modified onto sputtering the Au filter paper and gold nanoparticles (Au NPs) to link metal ions and acted as Raman signal molecules. All the LODs for metal ions were down to 1 μM. Due to the easiness of fabrication, good reproducibility, and simple pretreatment step, the PC-SERS platform holds promise in multicomponent detection in a real sample.

Fluorescent Test Paper via the In Situ Growth of COFs for Rapid and Convenient Detection of Pd(II) Ions

“…At present, the detection methods of palladium ions mainly include spectroscopic and electrochemical analyses. − Although these methods are accurate and sensitive, the instruments are expensive, tedious to operate, and inconvenient to carry. , Thus, they are not suitable for on-site rapid detection. In contrast, the test paper has the advantage of convenience, is fast, green and safe, and cheap and has been widely used in the fields of medical and health, food safety, and environmental protection. − However, the applications and reports of the COF-based test paper method in detecting heavy metal elements are still relatively few. The idea of inventing a test paper for the rapid detection of Pd 2+ indeed originated from this situation.…”

Facile Synthesis of Water-Soluble Rhodamine-Based Polymeric Chemosensors via Schiff Base Reaction for Fe3+ Detection and Living Cell Imaging

“…The determination of Fe 3+ in natural water or human body fluid is of great importance to human health and biological environment. Among the numerous detection assays, such as atomic absorption ( Frankowski et al, 2010 ), mass spectrometry ( Jia et al, 2018 ), Raman scattering ( Song et al, 2020 ), and so on, optical spectroscopy methods combined with molecular sensors have attracted much attention for the characteristics of easy operation, high sensitivity, and high throughput ( Cao et al, 2014 ; Jin et al, 2018 ; Jung et al, 2019 ). Many chemosensors for Fe 3+ have been developed, but very few can be directly applied in water or biological samples due to their intrinsic hydrophobicity and cytotoxicity ( Carter et al, 2014 ; Hou et al, 2017 ).…”

Utilizing Heterostructured Porous Particles to Improve Traditional Paper Chromatography for Spontaneous Protein Separation

“…On the basis of liquid self-transport, lateral flow strips and paper-based microfluidics − for sensitive protein, − DNA, , and RNA − detection have been fabricated, which shows great potential in resource-poor areas. Moreover, paper chromatography has been used to separate organics − and inorganic metal ions , since Martin used two-dimensional paper chromatography to complete the qualitative analysis of proteins. − It might be promising in self-driven protein separation.…”