Analyst Blog

Differentiating quadruplexes from duplexes using silver nanoparticles and SERS

A promising drug target and ligand-binding site, G-quadruplexes form via Hoogsteen hydrogen bonding in guanine bases. These quartets are rich in guanine and are stabilized through π-π stacking interactions and a cation such as potassium or sodium. As researchers explore new compounds to target this region to treat diseases such as cancer, the structure of these quadruplexes and their response to ligands compared to standard DNA remains understudied. 

Researchers at the University of Strathclyde have used the sensitivity of surface-enhanced Raman spectroscopy (SERS) to detect the formation of G-quadruplexes in the presence of stabilizing ligands and silver nanoparticles. They successfully differentiated the quadruplex DNA structure from the duplex based on the SERS signal, and demonstrated the capability of SERS in identifying higher order DNA structures. To read more about the qualitative detection of these structures, click the link below. It will be free to read until June 30. 

Graphene-polyfuran hybrids for Hg sensing

Commonly associated with dental fillings, mercury has a wide range of industrial and domestic applications. However, it can be toxic to humans and the environment even in small concentrations, and has been linked to a number of fatal diseases including pulmonary edema and cyanosis.

Previously developed methods of mercury detection include photochemical, colorimetric and oligonucleotide-based approaches. However, these methods can be slow, expensive and associated with low sensitivity and selectivity for the analyte. Graphene composite materials, with their unusual and enhanced conductivity properties, are an attractive prospect for metal ion analysis.

Researchers led by Professor Jyongsik Jang at the Seoul National University, Korea, have developed a new class of graphene oxide-polyfuran nanotube hybrids. In this “HOT” Analyst paper, the authors test the potential of their graphene-based materials as high performance sensors for mercury ion detection. This method has proved to be highly selective for Hg²⁺ over other metal ions and has excellent sensitivity even at low mercury concentrations.

This article will be free to read until 30th June.

High-performance Hg²⁺ FET-type sensors based on reduced graphene oxide–polyfuran nanohybrids
Jin Wook Park, Seon Joo Park, Oh Seok Kwon, Choonghyen Lee and Jyongsik Jang
Analyst, 2014, Advance Article
DOI: 10.1039/C4AN00403E