Sensitive CVG-AFS/ICP-MS label-free nucleic acid and protein assays based on a selective cation exchange reaction and simple filtration separation. Issue 8 (18th March 2019)

• Record Type: Journal Article
• Authors: Chen, Piaopiao; Huang, Ke; Dai, Rui; Sawyer, Erica; Sun, Ke; Ying, Binwu; Wei, Xiawei; Geng, Jia
• Is Part Of: Analyst. Volume 144:Issue 8(2019)
• Page Start: 2797
• Page End: 2802
• Publication Date: 2019-03-18
• Subjects: Chemistry, Analytic -- Periodicals; 543
• DOI: 10.1039/c8an01926f
• Languages: English
• ISSNs: 0003-2654

Abstract

Abstract : Sensitive CVG-AFS/ICP-MS label-free nucleic acid and protein assays based on a selective cation exchange reaction and simple filtration separation. Abstract : Nowadays, label-free atomic spectrometric bioassays are attracting great research interest because of their advantages of low cost, simple design and operation, etc . Herein, a novel and simple chemical vapor generation-atomic fluorescence spectrometry (CVG-AFS)/inductively coupled plasma-mass spectrometry (ICP-MS) label-free detection method is presented for highly sensitive and selective assay of DNA and proteins. This work mainly combined a phenomenon that CdTe quantum dots (QDs) can be used to selectively differentiate free Hg 2+ and the T–Hg 2+ –T complex, with the use of simple membrane filtration separation to improve the performance of the label-free bioassay methods. Upon hybridization with the DNA/protein (carcinoembryonic antigen, CEA) target, the T–Hg 2+ –T hairpin structure was opened and Hg 2+ was released; this initiated the cation exchange reaction between Hg 2+ and CdTe QDs which released Cd 2+ simultaneously. Subsequently, the free Cd 2+ was separated by the filtration membrane without separating the CdTe QDs, which could then be separated from the sample matrices for the CVG-AFS/ICP-MS assay. Under the optimal conditions, this method possessed high sensitivity for DNA and CEA determination with limits of detection (LODs) of 0.2 nM and 0.2 ng mL −1, and linear dynamic ranges of 1–160 nM and 0.5–20 ng mL −1, respectively, and exhibited excellent DNA sequence specificity and protein selectivity. This method preserves the advantages of the label-free atomic spectrometric bioassay, and combined with the selective cation exchange reaction and simple filtration separation to improve the performance.