Surface-Enhanced Raman Scattering for arsenic detection and discrimination

Description

Arsenic (As) is one of the most toxic contaminants found in the environment and especially in water. The World Health Organization decrees an As concentration less than 10 µg/L (10ppb). Established laboratory method is mass spectrometry. This technique is costly and time-intensive [1]. Other methods for As detection in water are in state of research (biosensor, electrochemical sensor, Surface Enhanced Raman Scattering sensor) (Figure1) SERS sensors are known for their high sensitivity for chemical compounds detection like pesticides [2]. In this study, we compare two kinds of silver (Ag) SERS substrates differentiating by their elaboration process. Figure 2 shows SERS results of As detection at a concentration of 10 ppb obtained with substrates made by an electroless process. Bands at 730 cm-1 and 830 cm-1 are the signature of the symmetric stretching vibrations As-O for As(3) and As(5) respectively [3] [4]. Uptake of As in water by nanostructured Ag films is discussed. References: [1] M. Singh and M. del Valle, Arsenic Biosensors: Challenges and Opportunities for High-Throughput Detection, Handbook of Arsenic Toxicology, 575-588 (2015) [2] J.

Abstract

International audience

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