“Turn-On” Chemiluminescence Sensor for the Highly Selective and Ultrasensitive Detection of Hg²⁺ Ions Based on Interstrand Cooperative Coordination and Catalytic Formation of Gold Nanoparticles

Abstract

Monitoring the levels of potentially toxic metal ions such as Hg(2+) in aquatic ecosystems is important because this ion can have severe effects on human health and the environment. Thus, a novel chemiluminescence (CL) sensor is developed for the highly selective and ultrasensitive detection of Hg(2+) ions in aqueous solution, based on thymine-Hg(2+)-thymine (T-Hg(2+)-T) coordination chemistry and subsequent formation of gold nanoparticles (Au NPs) in a HAuCl(4)/NH(2)OH reaction. The thus-formed Au NPs trigger the reaction between luminol and AgNO(3), producing CL emission. This novel CL technique has several advantages including high sensitivity (0.01 ppb) and selectivity over a spectrum of interfering metal ions. In view of these advantages, as well as the cost-effective, minimized working steps and portable features of the CL techniques, we expect that this CL sensor will be a promising candidate for the field detection of toxic Hg(2+) ions in environment, water, and food samples.

Nucleic Acids With Metal‐Mediated Base Pairs and Their Applications

“…A different approach relies on the formation of T‐Hg‐T base pairs to pre‐arrange the resulting DNA scaffold for additional binding of Ag + that can then be reduced in situ to generate fluorescent silver nanoparticles, thereby indicating the presence of Hg 2+ with a detection limit of 10 n M 72. A similar system has been reported in which the presence of T‐Hg‐T base pairs catalyses the formation of gold nanoparticles that in turn trigger the reaction of luminol and AgNO 3 to produce chemiluminescence 73. The attachment of semiconductor quantum dots to an oligonucleotide sequence capable of forming metal‐mediated base pairs allows the selective analysis of the respective metal ion by opening up an electron‐transfer‐quenching path upon incorporation of the metal ion, which leads to a decrease in luminescence of the semiconductor quantum dot 74…”

Excited Oxidized-Carbon Nanodots Induced by Ozone from Low-Temperature Plasma to Initiate Strong Chemiluminescence for Fast Discrimination of Metal Ions

“…[21][22][23] However the previously reported CL-based techniques normally required the addition of strong oxidants and liquid CL reagents into the system. 24,25 Therefore, more simple CL-based methods are still encouraged for the detection of metal ions.…”

“…As reported, changes of signals might attribute to the electron, charge or energy transfer caused by the selective interaction between metal ions and C-dots. 24,[40][41][42] Specifically, it is likely to form complexes between Fe 3+ and phenolic hydroxyls at Cdots which could facilitate charge transfer and thus constrain excitation recombination, 43 resulting in significant decrease of CL signals. As for Zn 2+ , a rigid structure may be formed through the complexation between Zn 2+ and C-dots, which would lead to the enhancement of CL due to the energytransfer interaction of them.…”

A highly sensitive chemiluminescence sensor for detecting mercury (II) ions: a combination of Exonuclease III-aided signal amplification and graphene oxide-assisted background reduction

“…To overcome this shortcoming, Exonuclease III (Exo III), a nuclease that catalyzes the stepwise removal of mononucleotides from doi: 10.1007/s11426-014-5258-9 3′-hydroxyl termini of duplex DNAs, was introduced [20]. Accordingly, a sequence-independent strategy, Exo IIIaided signal amplification, was developed to "recycle" target molecules, resulting in improved sensitivity [21][22][23].…”