A dual-model SERS and RRS analytical platform for Pb(II) based on Ag-doped carbon dot catalytic amplification and aptamer regulation

Haidong Wang,Zhiliang Jiang,Guiqing Wen,Xiaowei Huang

doi:10.1038/s41598-019-46426-y

Haidong Wang, Zhiliang Jiang + Show 2 more

Open Access

https://doi.org/10.1038/s41598-019-46426-y

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Journal: Scientific Reports	Publication Date: Jul 10, 2019
Citations: 14	License type: open-access

Affiliation: Guangxi Normal University

Abstract

Several carbon dots doping with diferent elements (Ca, Ag, Au) were fabricated and their catalytic properties had been investigated in this paper. It was found that the Ag-doped carbon dots (CDAg) had played a role of mimic enzyme on the reaction of HAuCl4-H2O2 and generated nanogold particles with surface enhanced Raman scattering (SERS) and resonance Rayleigh scattering (RRS) effects. The aptamer (Apt) can be adsorbed on the CDAg surface and cause the catalysis weakening. When the target Pb(II) was added, it would combine with the Apt to produce firm complexes Pb-Apt and desorb CDAg, which caused its catalytic effect restore. The formed nanogold had a strong RRS peak (at 375 nm) and a high SERS peak (at 1615 cm−1) in the presence of molecular probe (Victoria blue B, VBB). The dual-model signals of SERS and RRS increased linearly with Pb(II) concentration increase within the scope of 0.006–0.46 μmol/L and 0.01–0.46 μmol/L. And their detection limits respectively were 0.0032 μmol/L and 0.0048 μmol/L Pb(II).

Highlights

surface enhanced Raman scattering (SERS) refers to a phenomenon of Raman scattering signal enhancement caused by the adsorption of certain molecules on the surface of nano-sized rough metal[11,12,13]
In the aptamer-regulated system, the aptamer can bind to the catalyst, inhibiting its catalytic action and linearly reducing the SERS signals of the system (Fig. S12)
After adding Pb(II), it can bind to Apt, which activates the catalytic activity of CDCa/CDAg0-3/CDAu2 and accelerates the reaction

Summary

Introduction

SERS refers to a phenomenon of Raman scattering signal enhancement caused by the adsorption of certain molecules on the surface of nano-sized rough metal[11,12,13]. Ouyang et al.[16] reported a aptamer coupled SERS tenique for the determination of 0.13–53.33 nmol/L Pb(II) by using the catalysis of gold nanoparticle (AuNP) on the reduction of HAuCl4-H2O2. Zhang et al.[18] demonstrated the determination of alkaline phosphatase activity (APA) with a dual-mode (colorimetric and fluorescent) method by sensing with a kind of composite core-shell nanoparticles This dual-mode study provided a new sensing tenique with the well application of the optical properties of AuNPs and the luminescence properties of polymers. Based on the linear change of RRS intensity with the addition of Bi(III) since the reduction of Bi(III) will consume I3− and there was energy transfer (RRS-ET) between I3− and graphene oxide (GO), Liang et al built a dual-model RRS/ SERS method for Bi(III) with a linear range of 0.05–5.5 μmol/L and a DL of 4 ng/mL24. The new method could detect 0.1–75 nM Pb2+, and the DL was 37 pM

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