Mercury Ion Sensor Research Articles

A Wide Detection Range Mercury Ion Sensor Using Si MOSFET Having Single-Walled Carbon Nanotubes as a Sensing Layer

This letter investigates the response of a wide detection range mercury ion sensor based on Si MOSFET having a floating-gate (FG) and a control-gate (CG) in horizontal direction. Single-walled carbon nanotubes (SWNTs) are formed between the FG and the CG by using an inkjet-printing method. The interaction between themercury ions and SWNTs is studied by measuring transient current response ( I–t ). Conductance change is measured from 1 fM to $\sim 10~\mu \text{M}$ in saturated transient current region. The measured transient response shows that the drain current ( ${I}_{{D}}$ ) is appreciably changed in p MOSFET sensor and almost notchanged in n MOSFET sensor. By analyzing the conductance change of the p MOSFET sensor with the concentration of mercury ions, it is shown that the work-function of SWNTs increases due to hole doping and the ${I}_{{D}}$ increases as a result.

Novel selective and sensitive dual colorimetric sensor for mercury and lead ions derived from dithizone-polymeric nanocomposite hybrid

In this study, a new colorimetric sensor based on dithizone-anchored poly (vinyl pyridine – N,N-methylenebisacrylamide- acrylic acid) (poly (2-VP-MBAm-AA)) nanocomposite with a simple procedure was prepared for detection of mercury and lead ions trace levels in aqueous media.The incorporation of selectivity characteristics into colorimetric sensor was studied and the results of metal detection capacity showed the strong affinity toward Hg(II) and Pb(II). The specific detection of the optical sensor is attributed to the selective interaction between Hg(II) and Pb(II) with electron pair of N and S groups of immobilized dithizone on a nanocomposite membrane in aqueous media which was distinguished by naked eye and UV–vis spectrophotometer. The color of the resultant colorimetric sensor in the presence of Hg(II) and Pb(II) Shifted to violet and red, respectively. This new nanocolorimetric sensor displayed the advantages such as: rapidity, selectivity, sensitivity and suitability for detection of favorite ions up to 10ppb in aqueous solution. The results indicated that dithizone-anchored poly (2-VP-MBAm-AA) nanocomposite can be potentially used as a colorimetric sensor for real sample analysis.The distinctive features of this novel naked-eye optical sensor in determination of toxic metals ion are simplicity, more sensitivity and no need to the sophisticated devices.

Hassle free synthesis of nanodimensional Ni, Cu and Zn sulfides for spectral sensing of Hg, Cd and Pb: A comparative study

A simple room temperature synthesis method of Ni, Cu and Zn sulfide nanoparticles (NPs) in aqueous medium is reported here. The NPs stabilized in aqueous medium by the citrate ions were characterized by UV–vis, ζ potentials, TEM and Raman spectroscopic techniques. The solid NPs could be isolated from the aqueous medium when allowed to stand for a prolonged time (~20h). The solids were also characterized by IR and powder X-ray analysis. The nanoparticles were further used for the development of facile optical sensing and detection of heavy metal ions at trace scale. Alterations in the absorption spectra of the generated NPs were indicative of their interactions with heavy metal ions. Raman spectral measurements further validate the detection technique. It is found that out of the three synthesized nanoparticles, nickel sulfide NP is a specific sensor for mercury ions whereas zinc sulfide and copper sulfide NPs act as sensors for Hg2+, Cd2+ and Pb2+.

Turn-on fluorescence sensor based on naphthalene anhydride for Hg2+

A novel fluorescence sensor for mercury ions based on Hg2+ triggered desulfurated conversion has been designed and synthesized. The sensor shows high sensitivity to Hg2+ with about 40-fold increase in fluorescence intensity and high selectivity over a wide range of common cations in CH3CNH2O (7/3, v/v) buffered with 4-(2-hydroxyethyl)-1-pip-perazineethanesulfonic acid (HEPES) (pH=7.4, 0.02 M). An obvious green fluorescence can be observed by naked eyes upon addition of Hg2+ under a UV lamp, thus it provides an easy and efficient way to detect Hg2+.

Novel electrochemiluminescence of perylene derivative and its application to mercury ion detection based on a dual amplification strategy

In this paper, a novel covalently crosslinked perylene derivative (PTC-PEI) composed of polyethylenimine (PEI) and perylenetetracarboxylic acid (PTCA) has been first investigated for cathodic electrochemiluminescence (ECL) in an aqueous system with dissolved O2 as coreactant. The promising novel ECL materials of PTC-PEI exhibited admirable physical and chemical stability and high ECL intensity, which held an alternative way to construct ECL sensor with improved sensitivity. Thus, it was applied to construct a dual amplified “signal-on” mercury ion (Hg2+) sensor by the employment of nicking endonuclease (NEase)-assisted target recycling and rolling circle amplification (RCA) for signal amplification. Herein, a long G-rich sequence was generated by RCA process to capture abundant hemin on the electrode surface, and then a significantly amplified ECL signal of PTC-PEI was obtained. Based on dual signal amplification strategy, the devised sensor showed a linear range from 0.1pM to 0.1μΜ with a detection limit down to 33fM (S/N=3), and was successfully used in the direct detection of real water sample with high sensitivity and selectivity.

L-Tryptophan-capped carbon quantum dots for the sensitive and selective fluorescence detection of mercury ion in aqueous solution

l-Tryptophan-capped carbon quantum dots (l-CQDs) were facilely synthesized through “green” methodology, and the obtained material was utilized as a sensitive and selective fluorescence sensor for mercury ion (Hg2+) in pure aqueous solutions. Carboxyl-functionalized CQDs were first green synthesized by a one-step hydrothermal route, and l-tryptophan was then attached to CQDs via direct surface condensation reaction in aqueous solution at room temperature. The as-synthesized l-CQDs had an average size of ca. 5 nm with a good dispersity in water, and exhibited a favorable selectivity for Hg2+ ions over a range of other common metal cations in aqueous solution (10 mM PBS buffer, pH 6.0). Upon the addition of Hg2+, a complete fluorescence quenching (ON–OFF switching) of l-CQDs was evident from the fluorescence titration experiment, and the fluorescence detection limit of Hg2+ was calculated to be 11 nM, which indicated that the obtained environmentally friendly l-CQDs had sensitive detection capacity for Hg2+ in aqueous solution.

A fully-aqueous red-fluorescent probe for selective optical sensing of Hg2+ and its application in living cells

A new red-fluorescent mercury ion sensor material is designed and synthesized, which is composed of a tweezer-shaped hydrophilic probe containing bifurcated soft-base atoms N and S coupled with 2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran (TCF) unit. By virtue of the strong electron-accepting nature of TCF unit (as a push–pull chromophore), this designed sensor material can selectively detect Hg2+ over various tested metal ions in a 100% aqueous medium via naked-eye and photoluminescence (PL) observations. Theoretical and time-resolved photoluminescence measurements further confirmed the selectivity and reversibility of the probe towards Hg2+ via intramolocular charge transfer mechanism in this sensor material. Moreover, the living cell tests by confocal fluorescence images of this sensor material towards Hg2+ were also investigated. Finally, distinguished absorption changes and fluorescence quenching spectral appearances allowed us to present the selective optical indicator of Hg2+ via TCF moiety for the first time.

Pulsed Laser-Driven Molecular Self-assembly of Cephalexin: Aggregation-Induced Fluorescence and Its Utility as a Mercury Ion Sensor.

A fluorescent self-assembly of cephalexin is obtained by pulsed laser irradiation process. An intense fluorescence emission is found in the self-assembled form due to occurrence of a typical aggregation-induced emission in cephalexin molecules. It is observed that fluorescence quenching of the self-assembled fluorescent nanostructures occurs in the presence of extremely low Hg(++) ions concentrations (10(-7) m) as compared to other heavy metal ions e.g. Ferrous (Fe(++) ), Manganese (Mn(++) ), Magnesium (Mg(++) ), Cobalt (Co(++) ), Nickel (Ni(++) ) and Zinc (Zn(++) ) at the same concentrations.

Two-dimensional FeS nanoflakes: synthesis and application to electrochemical sensor for mercury(II) ions

We report a facile solvothermal method to prepare troilite FeS two-dimensional nanoflakes. The morphology and size were observed by transmission electron microscopy (TEM), the intrinsic crystallography of the obtained FeS nanoflakes was characterized by powder X-ray diffraction and high-resolution TEM, and the composition was analyzed by X-ray photoelectron spectroscopy. Furthermore, the prepared FeS nanoflakes were successfully modified on an electrode to fabricate a sensor for Hg2+ detection. The electrochemical detection mechanism was expected that Hg2+ ions interact with FeS to form stable HgS in the nanoflakes, which provided a sensitive approach for electrochemical detection of Hg2+ selectively. The detection limit for Hg2+ was 4 nM in a PBS solution. The prepared sensor based on the FeS nanoflakes shows the better performance than that with bulk-FeS materials for the Hg2+ detection. The proposed FeS nanoflakes also exhibit good applicability for monitoring Hg2+ in real water specimens.

Novel styrylbenzothiazolium dye-based sensor for mercury, cyanide and hydroxide ions

We report the design and synthesis of a novel styrylbenzothiazolium (3) derivative developed as a fluorescent and colorimetric chemodosimeter with high selectivity toward Hg2+, CN− and OH− ions. An obvious loss of pink color in the presence of Hg2+ and CN− ions could make it a suitable “naked eye” indicator. We propose a sensing mechanism whereby the benzenoid form is changed to a quinoid form upon Hg2+ binding in a 1:1 stoichiometric ratio. More significantly, the styrylbenzothiazolium-Hg2+ and styrylbenzothiazolium-CN− complexes exhibited a dual-channel chromo-fluorogenic response. The sensors exhibit remarkable Hg2+-, CN−-, and OH−-selective red fluorescence but remain dark-green in the presence of a wide range of tested metal ions and anions.

A novel fluorescent sensor for mercury (ii) ion using self-assembly of poly(diallyl dimethyl ammonium)chloride functionalized CdTe quantum dots

A novel fluorescent sensor was constructed for selective quantitative analysis of mercury(ii) ion based on poly(diallyl dimethyl ammonium)chloride (PDDA) functionalized CdTe quantum dots.

Highly sensitive and portable mercury(ii) ion sensor using personal glucose meter

A highly sensitive and portable mercury(ii) ion sensor based on personal glucose meter (PGM) recording is reported.

A mercury(II) ion sensor device based on an organic field effect transistor with an extended-gate modified by dipicolylamine.

Herein, we report an organic field effect transistor (OFET) with an extended-gate modified by an artificial receptor for the detection of mercury(II) ions (Hg(2+)) in water. The sensor device is easy to fabricate, reusable, disposable, and portable. Thus OFET sensors could be applied for low-cost on-site detection of Hg(2+).

Highly sensitive SERS sensor for mercury ions based on the catalytic reaction of mercury ion decorated Ag nanoparticles

Schematic diagram of the SERS sensing mechanism for mercury ions by a catalytic oxidation reaction.

Raman Spectroscopy of Di‐(2‐picolyl)amine on Gold Nanoparticles for Hg(II) Detection

In an effort to develop a spectroscopic mercury ion sensor, the Raman spectral features of di‐(2‐picolyl)amine (DPA) on gold nanoparticles (AuNPs) were examined in the presence of various ions. The two bands at 1020 and 1060 cm−1 showed different intensities in the presence of Hg2+ , whereas the other ions, Pb2+ , Ni2+ , NH4 +, Na+ , Mn2+ , Mg2+ , K+ , Zn2+ , Fe2+ , Cd2+ , Cu2+ , Cr3+ , Co2+ , Fe3+ , and Ca2+ at the same concentrations of 100 μM did not produce such spectral changes. The band at 1060 cm−1 became stronger than that at 1020 cm−1, only for Hg2+ . These two bands may correspond to the ring‐breathing and trigonal ring‐breathing vibration of the two pyridine rings of DPA. The Hg(II) concentration‐dependent surface‐enhanced Raman scattering (SERS) spectra indicated that the relative intensities of the two bands reversed above 10 μM. In addition to this noteworthy feature, the bands at 270 cm−1, which may be ascribed to the Au—N stretching, show much higher intensities in the presence of Hg2+ . Our Raman spectral analysis of DPA may be useful to discriminate the Hg2+ ion above 10 μM using AuNPs on the basis of molecular vibrational spectroscopy.

Photoelectrochemical determination of inorganic mercury ions based on energy transfer between CdS quantum dots and Au nanoparticles

A novel photoelectrochemical (PEC) sensor for mercury ions (Hg2+) was fabricated based on the energy transfer (ET) between CdS quantum dots (QDs) and Au nanoparticles (NPs) with the formation of T–Hg2+–T pairs. In the presence of Hg2+ ions, a T-rich single-strand (ss) DNA labeled with Au NPs could hybridize with another T-rich ssDNA anchored on the CdS QDs modified electrode, through T–Hg2+–T interactions, rendering the Au NPs in close proximity with the CdS QDs and hence the photocurrent decrease due to the ET between the CdS QDs and the Au NPs. Under the optimal condition, the photocurrent decrease was proportional to the Hg2+ concentration, ranging from 3.0×10−9 to 1.0×10−7M, with the detection limit of 6.0×10−10M.

Synthesis of catalytically active silver nanoparticles using lipid derived signaling molecule, N-steroylethanolamine: Promising antibacterial agent and selective colorimetric sensor for mercury ion

A facile method was reported for preparing silver nanoparticles (AgNPs) based on naturally occurring N-acylethanolamine (NAE) as a capping agent and sodium borohydride as a reducing agent. NAEs have been found in the infracted areas of canine myocardium and ischemic brain tissues. AgNPs prepared by N-steroylethanolamine (NSEA) are very stable and can be reliably and reproducibly synthesized. These particles have a capability to selective colorimetric sensing of the potentially hazardous Hg2+ ion in water at micromolar concentration. The proposed method was successfully employed for the determination of Hg2+ ion in blood plasma and also in various water bodies, such as tap water, pond water and sewage water. Further, degradation of hazardous organic pollutant, methylene blue dye, was explored using NSEA–AgNPs as catalyst. Besides selective sensing of Hg2+ and degrading hazardous dye, NSEA–AgNPs also shows excellent catalytic activity in the reduction of nitro aromatics. In addition, NSEA–AgNPs shows bactericidal effect in Gram-positive and Gram negative test bacteria, for which the values of minimum inhibitory concentration were determined and reported. In summary, the NSEA–AgNPs reported in this work was a promising candidate for versatile application, such as a sensor, antimicrobial and catalyst.

Selective fluorescent sensor for mercury(II) ion based on an easy to prepare double naphthalene Schiff base

A fluorescent mercury sensor allowing for cheap, sensitive, and highly selective detection of Hg2+ is described. This sensor combines two naphthalene groups as signaling subunits and the presence of imine group which was oxidized to amide with DMSO and Hg2+ confers the coordination capacity required to coordinate Hg2+ ion. This double-naphthalene Schiff base chemosensor (G, Scheme 2) is readily soluble in DMSO and the solution give colorless fluorescent signal, when sensor G reacts with Hg2+ the solution give blue fluorescent signal. The MS, IR and 1H NMR data suggest that the presence of Hg2+ leads to the formation of OHg2+N, which is then converted to a structural change, the CN of G was oxidized to OCNH of G1 (Scheme 1). The test strip based on G was fabricated, which could act as a convenient and efficient Hg2+ test kit. The event is useful for fluorescent detection of Hg2+ at the micromolar level with a detection limit of 5.595×10−8M in DMSO medium.

A highly sensitive label-free sensor for Mercury ion (Hg2+) by inhibiting thioflavin T as DNA G-quadruplexes fluorescent inducer

DNA sequences with guanine repeats can be induced to form G-quartets that adopt G-quadruplex structures in the presence of thioflavin T (ThT). ThT plays a dual role of inducing DNA sequences to fold into quadruplex structures and of sensing the change by its remarkable fluorescence enhancement. ThT binding to the DNA sequences with guanine repeats showed highly specific fluorescence enhancement compared with single/double-stranded DNA. In this work, we have utilized the conformational switch from G-quadruplex complex induced by fluorogenic dye ThT to Hg(2+) mediated T-Hg-T double-stranded DNA formation, thereby pioneering a facile approach to detect Hg(2+) with fluorescence spectrometry. Through this approach, Hg(2+) in aqueous solutions can be detected at 5 nM with fluorescence spectrometry in a facile way, with high selectivity against other metal ions. These results indicate the introduced label-free method for fluorescence spectrometric Hg(2+) detection is simple, quantitative, sensitive, and highly selective.

Hydrothermal growth of CuO nanoleaf structures, and their mercuric ion detection application.

Mercury is the hazardous heavy metal ion for the environment and the human being therefore its determination is very important and herein we describe the development of mercury ion sensor on the CuO nanoleaf like nanostructures using cetyltrimethylammonium bromide (CTAB) surfactant as template for the growth by hydrothermal growth method. Scanning electron microscopy and X-ray diffraction study has shown high density and good crystal quality of the fabricated CuO nanostructures respectively. The presented mercury ion sensor has detected the wide range of 1.0 x 10(-7) to 1.0 x 10(-1) M mercury ion concentrations with an acceptable Nernstian behaviour and a sensitivity of 30.1 ± 0.6 mV/decade. The proposed mercury ion sensor exhibited low detection limit of 1.0 x 10(-8) M and also a fast response time of less than 5 s. In addition, the presented mercury ion sensor has shown an excellent repeatability, reproducibility, stability and selectivity. Moreover, the mercury ion selective electrode based on CuO nanoleaves was tested as an indicator electrode in the potentiometric titration.