Disposable cuvette test with integrated sensor layer for enzymatic determination of heavy metals

Preininger, Claudia; Wolfbeis, Otto S.

doi:10.1016/0956-5663(96)87657-3

Cited by 74 publications

(31 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of 0.006 pM Hg(II) and 100 btM Cu(II) in a citrate buffer (comb 3), the inhibition was almost exclusively due to the stronger inhibitor mercury. In contrast to previous studies [ 12], no synergistic effect of Cu(II) ions on the activity of acid urease was observed.…”

Section: Combinations Of Cu(ll) and Hg(ll)contrasting

confidence: 83%

“…Heavy metals that show the highest affinity to the sulfur groups and form the most stable sulfides are the most toxic to acid urease. This phenomenon is true for most SH-containing enzymes [12].…”

Section: Discussionmentioning

confidence: 95%

“…The ammonium-sensitive layer was glued to one wall of a 3.5x I cm 2 cuvette [12]. In order to measure 100% enzyme activity, solutions of 2.9 ml buffer and 0.2ml acid urease were placed in the cuvette.…”

Section: Test Principlementioning

confidence: 99%

“…Because of their unique characteristics biosensors might be exploited to fill specific niche applications in the environmental monitoring area [1]. Biosensors for the determination of phenols [2], formaldehyde [3], nitrates [4], pesticides [5,6], biological oxygen demand (BOD) [7][8][9] and heavy metals [10][11][12] have been reported.…”

mentioning

confidence: 99%

See 3 more Smart Citations

The enzymatic determination of mercury and copper using acid urease. The effects of buffers

Preininger

1999

Mikrochim Acta

Self Cite

View full text Add to dashboard Cite

Abstract. We report on a quick and simple test based on enzyme inhibition for the detection of mercury and copper using free acid urease coupled to an optical sensor system. Lipophilized Nile Blue was incorporated in plasticized poly(vinyl chloride) (PVC) to produce an ammonium-sensitive layer with a thickness of around 4 gin. The layer was fixed on one side of a disposable cuvette. A solution of buffer, enzyme and heavy metals was placed into the thermostated cell. Enzymatic hydrolysis was started upon addition of urea and the formation of ammonium was monitored. Mercury and copper were the strongest inhibitors; for this reason the inhibitory efficiency of these metals was examined in citrate, acetate and trismaleate buffers. The cuvette test was most sensitive and selective for mercury in a citrate buffer. The limit of detection for mercury(II) ions was as low as 1 gg/L. Copper ions do not interfere because of complexation by citrate. The inhibitory effects of metal combinations on the activity of acid urease and the effects of optimum pH of the enzyme and the transducer on the dynamic range of the cuvette test are presented.

show abstract

Section: Combinations Of Cu(ll) and Hg(ll)contrasting

confidence: 83%

Section: Discussionmentioning

confidence: 95%

Section: Test Principlementioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The enzymatic determination of mercury and copper using acid urease. The effects of buffers

Preininger

1999

Mikrochim Acta

Self Cite

View full text Add to dashboard Cite

show abstract

“…The ammonia generated thereby causes severe metabolic disorders besides causing severe damage to gastric epithelium through its interactions with the immune system in human beings [2,3]. In agriculture, high urease activity causes significant environmental and economical problems by releasing abnormally large amount of ammonia into the atmosphere during urea fertilization.…”

mentioning

confidence: 99%

In silico studies of urease inhibitors to explore ligand-enzyme interactions

Ansari

Wadood

Ullah

et al. 2008

Journal of Enzyme Inhibition and Medicinal Chemistry

View full text Add to dashboard Cite

In continuation of our previous study on the urease inhibition by a number of chalcones, 2,3-dihydro-1,5-benzothiazepines and 2,3,4,5-tetrahydro-1,5-benzothiazepines, FlexX docking has been exploited to get a deeper insight into the mechanism of their inhibitory action. A comparison of the IC 50 values of the active compounds reveals that, of the three classes of compounds studied, 2,3-dihydro-1,5-benzothiazepines were the most potent urease inhibitors. An in silico examination of these compounds showed that the activity is related to the interaction of ligand with the nickel metallocentre, its interaction with two amino acid residues, Asp224 and Cys322, in addition to the orientation of rings A and B in the catalytic core of the enzyme. The most active compound 2,3-dihydro-1,5-benzothiazepine (4) anchor tightly through a network of interactions with Ni701 and Ni702. This includes a number of hydrogen bonds and hydrophobic contacts with the amino acid residues in its vicinity. For their reduced analogs, the difference in the activity of different diastereomers has been observed to be configuration-dependent. This may be ascribed mainly to the difference in the orientation of ring B of the two stereoisomers and the extent of their interaction with Asp224 and Cys322 present in the catalytic core of the enzyme.

show abstract

Biosensor Array of Interpenetrating Polymer Network with Photonic Film Templated from Reactive Cholesteric Liquid Crystal and Enzyme‐Immobilized Hydrogel Polymer

Noh

Park

2018

Adv Funct Materials

103

View full text Add to dashboard Cite

A biosensor array is fabricated using an interpenetrating polymer network consisting of photonic film templated from reactive cholesteric liquid crystal (CLC) and enzyme‐immobilized polyacrylic acid (PAA). The solid‐state photonic film on the glass substrate is successfully templated by ultraviolet (UV) curing of the reactive CLC mixture of a reactive mesogen mixture of RMM 727 (from Merck) and a nonreactive chiral dopant of (S)‐4‐cyano‐4′‐(2‐methylbutyl)biphenyl following the extraction of the chiral dopant. The acrylic acid monomer mixed with a cross‐linker of tri(propylene glycol) diacrylate is infiltrated into the extracted space of the photonic film, and UV‐cured with a photomask to obtain a patterned array‐dot film. The interpenetrated cholesteric liquid crystal/hydrogel polymer network (CLC‐hydrogel‐IPN) array is further functionalized in the individual dots with urease, for a model study of biosensor array applications. The dots of the CLC‐hydrogel‐IPN array respond independently to the urea by a color change with high sensitivity and stability. Thus, the patterned CLC‐hydrogel‐IPN can be used as a new biosensor array for cost‐effective and easy visual detection without any sophisticated instruments.

show abstract

Disposable cuvette test with integrated sensor layer for enzymatic determination of heavy metals

Cited by 74 publications

References 27 publications

The enzymatic determination of mercury and copper using acid urease. The effects of buffers

The enzymatic determination of mercury and copper using acid urease. The effects of buffers

In silico studies of urease inhibitors to explore ligand-enzyme interactions

Biosensor Array of Interpenetrating Polymer Network with Photonic Film Templated from Reactive Cholesteric Liquid Crystal and Enzyme‐Immobilized Hydrogel Polymer

Contact Info

Product

Resources

About