A simple strategy to improve the sensitivity of probe molecules on SERS substrates

Chengbin Sun; Tingkun Chen; Weidong Ruan; Young Mee Jung; Qian Cong; Bing Zhao

doi:10.1016/j.talanta.2018.11.040

A simple strategy to improve the sensitivity of probe molecules on SERS substrates

Talanta. 2019 Apr 1:195:221-228. doi: 10.1016/j.talanta.2018.11.040. Epub 2018 Nov 24.

Authors

Chengbin Sun¹, Tingkun Chen², Weidong Ruan³, Young Mee Jung⁴, Qian Cong⁵, Bing Zhao³

Affiliations

¹ Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, PR China; Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chunchon 24341, Republic of Korea; State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, PR China.
² Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, PR China.
³ State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, PR China.
⁴ Department of Chemistry, Institute for Molecular Science and Fusion Technology, Kangwon National University, Chunchon 24341, Republic of Korea. Electronic address: ymjung@kangwon.ac.kr.
⁵ Key Laboratory for Bionic Engineering of Ministry of Education, Jilin University, Changchun 130025, PR China. Electronic address: congqian@jlu.edu.cn.

PMID: 30625535
DOI: 10.1016/j.talanta.2018.11.040

Abstract

In this work, we report a simple strategy to improve the detection sensitivity as well as the spectral quality of probe molecules on surface-enhanced Raman scattering (SERS) substrates. On normal SERS substrates, due to the decreased absorption capacity and changes in the molecule orientations, SERS signals disappear when the analyte molecule concentrations reach a limit value. To solve this problem, the molecular template reagent (MTR) technique, a simple strategy based on SERS surface selection rules, is considered. By choosing the best MTR according to different samples, the effect of adjusting the molecular orientations of samples can be studied. In this process, 1-butanethiol, 1-hexanethiol, 1-octanethiol, 1-decanethiol, and 1-dodecanethiol, which are MTRs, are used to adjust the orientations of probe molecules under optimized conditions. The use of the MTR technique indicated that the limit of detection (LOD) of the probe molecules of p-aminobenzenethiol and 4-mercaptobenzoic acid on noble metal substrates showed an increase of one order of magnitude over the LOD of the pure probing molecule systems. Hence, the proposed method introduces a way to detect the molecules with an improved sensitivity at extremely low concentrations. The study corresponds to a proof-of-concept study of MTR-assisted SERS for SERS-based applications in ultrasensitive analyses.

Keywords: Molecular template reagent (MTR); SERS substrates; Surface-enhanced Raman scattering (SERS); Ultrasensitive analyses.