A novel three-dimensional Zn-based metal-organic framework fluorescent probe for highly sensitive and selective detection of Hg2+ and Cr2O72− ions

An aggregation-induced emission fluorescent probe for highly sensitive and selective detection and imaging of Hg2+ in living cells

An interesting fluorescent probe with aggregation-induced emission for highly sensitive and selective detection of Hg2+

A simple and fast colorimetric method is developed for the sensitive and selective detection of Hg(2+) based on a dual signal amplification strategy: in situ Hg(2+) induced catalytic synthesis of oxidase-like AuHg nanoparticles and subsequent catalytic oxidation of TMB by AuHg nanoparticles.

A simple and highly effective Schiff-base fluorescent chemosensor (S1) was synthesized and characterized by 1HNMR and fluorescence spectroscopy. The synthesized chemosensor was applied for the selective and sensitive detection of Hg2+ ions. The chemosensor exhibited a strong 'turn-on' fluorescence response in a CH3OH/H2O (1:9, v/v) solution due to complex formation (S1-Hg2+) which block photo induce electron transfer (PET). The chemosensor showed significant sensitivity with very low detection limit of 2.0 ppb, making it suitable for trace-level Hg2+ detection. Furthermore, the S1-Hg2+ complex demonstrated excellent antibacterial activity against various Gram-positive and Gram-negative bacterial strains, broadening its utility beyond sensing. This dual-functional system offers significant potential in environmental and biomedical applications.

Anodized screen-printed electrode modified with poly(5-amino-4H-1,2,4-triazole-3-thiol) film for ultrasensitive detection of Hg2+ in fish samples

Sensitive and selective detection of Hg(II) contamination is of great importance with concern of public health. Herein, we successfully fabricated monolayer MoS2 (S-MoS2) decorated Cu7S4-Au (Cu7S4-Au@S-MoS2) nanocomposite modified electrode for the sensitive and selective detection of Hg(II) via anodic stripping voltammetric technique. Due to the excellent electrocatalytic reduction performance arisen from the abundant active edge sites of small monolayer MoS2 and good affinity of Au toward Hg, the current method displayed high sensitivity (LOD = 190 nmol L−1) and enhanced selectivity. As control, nanostructures including Cu7S4-Au, Cu7S4@S-MoS2 and Cu7S4-Au@M-MoS2 (M: multilayer) were also investigated, but showed low response to Hg(II), suggesting that both Au domains and active edge sites of monolayer MoS2 have crucial synergistic effects on the high-performance for recognition of Hg(II). Moreover, the developed method displays satisfied performance for the detection of Hg(II) in real samples, which indicates its potentials in practical applications.

In this paper, we report on a simple, green strategy for the production of fluorescent 2,3-diaminophenazine (DAP) nanoparticles (NPs) by UV light irradiation of o-phenylenediamine (oPD) aqueous solution at room temperature for the first time. We further demonstrate the proof of concept that the DAP NPs can be used as a very effective fluorescent sensing platform for sensitive and selective detection of Hg(II) ions with a detection limit as low as 1 nM.

Sensitive and selective detection of Hg2+ in tap and canal water via self-enhanced ECL aptasensor based on NH2–Ru@SiO2-NGQDs

In this work, hybrid magnetic core-shell fibrous silica (Py-CoFe2O4/SiO2/KCC-1) as a fluorescence sensor has been developed for the sensitive and selective detection of Hg (II) ion. The pyrene-based derivatives are successfully functionalized within the magnetic core-shell fibrous silica (CoFe2O4/SiO2/KCC-1) and characterized by Scanning electron microscope, Transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, Vibrating sample magnetometry, N2 adsorption-desorption, and Thermo gravimetric analysis. The proposed hybrid sensor (Py-CoFe2O4/SiO2/KCC-1) exhibits external magnetic behaviour and exclusive fluorescence response for Hg (II) ions over other competitive metal ions. The functional material exhibits an enhanced fluorescence response in the presence of Hg (II) ions and this attributes a good linearity (R2= 0.9906) with a detection limit 4.1 × 10−9 M. These results indicate that the fibrous silica modification of the core-shell improved the fluorescence sensing performance for the detection of Hg (II) ions. In addition, hybrid sensor finds a potential application for detecting Hg (II) ions in real water samples.

Highly sensitive and selective detection of Hg 2+ using mismatched DNA and a molecular light switch complex in aqueous solution

A portable selective electrochemical sensor amplified with Fe3O4@Au-cysteamine-thymine acetic acid as conductive mediator for determination of mercuric ion

Sensitive and selective detection of Hg2+ in solution is a challenging work. An anodic stripping voltammetry with prestripping step at an in situ formed bismuth film modified glassy carbon electrode was proposed for detection of mercury(II) in solution. This prestripping step was able to decrease the background and improve the signal‐to‐noise ratio and thus enhance the sensitivity. With this method, highly sensitive and selective detection of Hg2+ with a ppt‐level detection limit of 0.5 ng L−1 could be achieved. Moreover, this method provides low interference, rapid and extreme simple and convenience, and hold great promise for in situ Hg2+ determination.

Hg2+ toxicity is one of the most common chemical poisonings that occurs mainly from drinking polluted water. In the current work, Phycocyanin (PC) was exploited as a fluorescent sensor for sensitive and selective detection of Hg2+ in an aqueous system. PC-Hg2+ interaction was monitored using a spectro-fluorometer under different buffered solutions at pH values of 6,7,8,9, or 10 above the isoelectric point of PC (5.18). A remarkable decrease of PC fluorescence intensity was observed under Tris-buffer at pH 6 upon the addition of increasing Hg2+ concentrations (1–120 nM). Under the maintained experimental conditions, the current sensor showed a good linear relationship with R2 = 0.9971 and a limit of detection as low as 0.7 nM was achieved. In addition, a notable selectivity of Hg2+ over other nine heavy metals (Cu2+, Zn2+, Pb2+, Mg2+, Mn4+, Li+, Fe3+, Co2+, and Al3+) was achieved in the presence of 120 nM of each metal. Moreover, the current fluorescent detection assay was also tested in real samples of pond water, and recoveries as well as relative standard deviations within the acceptable limits were recorded.

Loading of AuNCs with AIE effect onto cerium-based MOFs to boost fluorescence for sensitive detection of Hg2+

A highly sensitive and selective detection method for mercury(II) in aqueous samples was developed based on the use of an oligonucleotide-based label-free fluorescent probe. The novel design was composed of two oligonucleotides with partially complementary sequences and the label-free dye ethidium bromide (EB). The fluorescence signal was very low when EB was free in water solution. However, the fluorescence signal increased by nearly 15 times when the DNA duplex was present. This dsDNA–EB system was used as a fluorescent sensor for Hg2+. The presence of Hg2+ led to the release of EB from the grooves of dsDNA and the fluorescence intensity was quenched. In this investigation, the optimal concentrations of dsDNA and EB were 0.285 μM and 0.9 μM, respectively. The calibration curve was linear in the range of 30 to 120 nM for Hg2+ (R2 = 0.992), with a detection limit of 9.5 nM. The method was simple and convenient, and this sensor also provided potential applications for developing aptasensors.