Hierarchical Au nanoclusters electrodeposited on amine-terminated ITO glass as a SERS-active substrate for the reliable and sensitive detection of serotonin in a Tris-HCl buffer solution. Issue 42 (15th October 2019)

• Record Type: Journal Article
• Authors: Phung, Viet-Duc; Kook, Jeong-Keun; Koh, Do Yeung; Lee, Sang-Wha
• Is Part Of: Dalton transactions. Volume 48:Issue 42(2019)
• Page Start: 16026
• Page End: 16033
• Publication Date: 2019-10-15
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/c9dt03269j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : In this study, a SERS-active substrate was fabricated by electrodepositing hierarchical Au nanostructures on amine-terminated ITO (indium tin oxide) glass to achieve an enhanced Raman signal of 5-HT. Abstract : Although serotonin (5-HT) is one of the most important neurotransmitters that are responsible for critical roles in the central nervous system, only few studies have been reported on the reliable and sensitive detection of 5-HT by the SERS technique owing to the lower Raman cross-section and lack of a common extraction method of 5-HT. In this study, a SERS-active substrate was fabricated by electrodepositing hierarchical Au nanostructures on amine-terminated ITO (indium tin oxide) glass to achieve an enhanced Raman signal of 5-HT. The electrodeposition process was performed by applying the nucleation potential E 1 = 0.7 V for 2 s and the growth potential E 2 = −0.2 V for 1000 s for repeated cycles. As a testing analyte, 5-HT was dissolved in four different solvents i.e. PBS buffer, Tris-HCl buffer, distilled water, and ethanol solution (20%). Among them, Tris-HCl buffer produced the most sensitive and reproducible Raman signals for 5-HT along with the lowest detection limit of ∼10 −9 M due to the strong adsorption interactions between the Au surface and the indole amine groups of 5-HT under alkaline conditions. Surprisingly, the standard curve between the Raman intensity at 751 cm −1 and the log-scale concentration of 5-HT showed a linear dynamic range of over five orders of magnitude in the Tris-HCl buffer solution, suggesting a possible quantification of the 5-HT level in a biological fluid with 5-HT dysfunction or deficiency.