Colorimetric photonic hydrogel aptasensor for the screening of heavy metal ions

Abstract

We have developed a robust method for the visual detection of heavy metal ions (such as Hg(2+) and Pb(2+)) by using aptamer-functionalized colloidal photonic crystal hydrogel (CPCH) films. The CPCHs were derived from a colloidal crystal array of monodisperse silica nanoparticles, which were polymerized within the polyacrylamide hydrogel. The heavy metal ion-responsive aptamers were then cross-linked in the hydrogel network. During detection, the specific binding of heavy metal ions and cross-linked single-stranded aptamers in the hydrogel network caused the hydrogel to shrink, which was detected as a corresponding blue shift in the Bragg diffraction peak position of the CPCHs. The shift value could be used to estimate, quantitatively, the amount of the target ion. It was demonstrated that our CPCH aptasensor could screen a wide concentration range of heavy metal ions with high selectivity and reversibility. In addition, these aptasensors could be rehydrated from dried gels for storage and aptamer protection. It is anticipated that our technology may also be used in the screening of a broad range of metal ions in food, drugs and the environment.

A reusable thioether-rich crown-based fluorescent sensor for the detection and removal of mercuric ions

“…This method will complement the existing approaches for Hg 2+ removal [6][7][8][9]. Despite of several advantages, these existing approaches [28][29][30][31] are financially inapplicable to the purification of contaminated water. In this work, we designed and synthesized a naphthalimide-baesd bifunctional fluorescent sensor FS-G 4 by integrating the small molecular fluorescent probe onto the surface of the silica nanoparticles, realizing simultaneously detection and separation of mercuric ions.…”

Aptamer-Based Hydrogels and Their Applications

“…Reprinted with the permission from Ref. [118]. Copyright 2012 Royal Society of Chemistry hydrogel was that volume changes were visible to the naked eye down to femtomolar concentrations of proteins.…”

“…Aptamer sensors have been incorporated into colloidal photonic crystal hydrogel (CPCH) films that have been used to construct sensors for visual detection of heavy metal ions, such as Hg 2+ and Pb 2+ [118]. Colloidal crystals, which assembled from monodisperse nanoparticles, have been used to construct sensors [119][120][121][122][123].…”

Aptamer-Based Technology for Food Analysis

“…Using aptamer-functionalized colloidal photonic crystal hydrogel (CPCH) films, Ye et al [63] developed a robust method for the visual detection of heavy metal ions Hg(2+) and Pb(2+). These aptasensors could be used in the screening of a broad range of metal ions in food, drugs, and the environment, with high selectivity and reversibility.…”