A whole-cell biosensor for the detection of gold.
Geochemical exploration for gold (Au) is becoming increasingly important to the mining industry. Current processes for Au analyses require sampling materials to be taken from often remote localities. Samples are then transported to a laboratory equipped with suitable analytical facilities, such as I...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2013-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3739760?pdf=render |
| _version_ | 1811281412541644800 |
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| author | Carla M Zammit Davide Quaranta Shane Gibson Anita J Zaitouna Christine Ta Joël Brugger Rebecca Y Lai Gregor Grass Frank Reith |
| author_facet | Carla M Zammit Davide Quaranta Shane Gibson Anita J Zaitouna Christine Ta Joël Brugger Rebecca Y Lai Gregor Grass Frank Reith |
| author_sort | Carla M Zammit |
| collection | DOAJ |
| description | Geochemical exploration for gold (Au) is becoming increasingly important to the mining industry. Current processes for Au analyses require sampling materials to be taken from often remote localities. Samples are then transported to a laboratory equipped with suitable analytical facilities, such as Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) or Instrumental Neutron Activation Analysis (INAA). Determining the concentration of Au in samples may take several weeks, leading to long delays in exploration campaigns. Hence, a method for the on-site analysis of Au, such as a biosensor, will greatly benefit the exploration industry. The golTSB genes from Salmonella enterica serovar typhimurium are selectively induced by Au(I/III)-complexes. In the present study, the golTSB operon with a reporter gene, lacZ, was introduced into Escherichia coli. The induction of golTSB::lacZ with Au(I/III)-complexes was tested using a colorimetric β-galactosidase and an electrochemical assay. Measurements of the β-galactosidase activity for concentrations of both Au(I)- and Au(III)-complexes ranging from 0.1 to 5 µM (equivalent to 20 to 1000 ng g(-1) or parts-per-billion (ppb)) were accurately quantified. When testing the ability of the biosensor to detect Au(I/III)-complexes(aq) in the presence of other metal ions (Ag(I), Cu(II), Fe(III), Ni(II), Co(II), Zn, As(III), Pb(II), Sb(III) or Bi(III)), cross-reactivity was observed, i.e. the amount of Au measured was either under- or over-estimated. To assess if the biosensor would work with natural samples, soils with different physiochemical properties were spiked with Au-complexes. Subsequently, a selective extraction using 1 M thiosulfate was applied to extract the Au. The results showed that Au could be measured in these extracts with the same accuracy as ICP-MS (P<0.05). This demonstrates that by combining selective extraction with the biosensor system the concentration of Au can be accurately measured, down to a quantification limit of 20 ppb (0.1 µM) and a detection limit of 2 ppb (0.01 µM). |
| first_indexed | 2024-04-13T01:33:24Z |
| format | Article |
| id | doaj.art-8d97333a040c4b70b510322d55f0c14b |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-04-13T01:33:24Z |
| publishDate | 2013-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-8d97333a040c4b70b510322d55f0c14b2022-12-22T03:08:27ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-0188e6929210.1371/journal.pone.0069292A whole-cell biosensor for the detection of gold.Carla M ZammitDavide QuarantaShane GibsonAnita J ZaitounaChristine TaJoël BruggerRebecca Y LaiGregor GrassFrank ReithGeochemical exploration for gold (Au) is becoming increasingly important to the mining industry. Current processes for Au analyses require sampling materials to be taken from often remote localities. Samples are then transported to a laboratory equipped with suitable analytical facilities, such as Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) or Instrumental Neutron Activation Analysis (INAA). Determining the concentration of Au in samples may take several weeks, leading to long delays in exploration campaigns. Hence, a method for the on-site analysis of Au, such as a biosensor, will greatly benefit the exploration industry. The golTSB genes from Salmonella enterica serovar typhimurium are selectively induced by Au(I/III)-complexes. In the present study, the golTSB operon with a reporter gene, lacZ, was introduced into Escherichia coli. The induction of golTSB::lacZ with Au(I/III)-complexes was tested using a colorimetric β-galactosidase and an electrochemical assay. Measurements of the β-galactosidase activity for concentrations of both Au(I)- and Au(III)-complexes ranging from 0.1 to 5 µM (equivalent to 20 to 1000 ng g(-1) or parts-per-billion (ppb)) were accurately quantified. When testing the ability of the biosensor to detect Au(I/III)-complexes(aq) in the presence of other metal ions (Ag(I), Cu(II), Fe(III), Ni(II), Co(II), Zn, As(III), Pb(II), Sb(III) or Bi(III)), cross-reactivity was observed, i.e. the amount of Au measured was either under- or over-estimated. To assess if the biosensor would work with natural samples, soils with different physiochemical properties were spiked with Au-complexes. Subsequently, a selective extraction using 1 M thiosulfate was applied to extract the Au. The results showed that Au could be measured in these extracts with the same accuracy as ICP-MS (P<0.05). This demonstrates that by combining selective extraction with the biosensor system the concentration of Au can be accurately measured, down to a quantification limit of 20 ppb (0.1 µM) and a detection limit of 2 ppb (0.01 µM).http://europepmc.org/articles/PMC3739760?pdf=render |
| spellingShingle | Carla M Zammit Davide Quaranta Shane Gibson Anita J Zaitouna Christine Ta Joël Brugger Rebecca Y Lai Gregor Grass Frank Reith A whole-cell biosensor for the detection of gold. PLoS ONE |
| title | A whole-cell biosensor for the detection of gold. |
| title_full | A whole-cell biosensor for the detection of gold. |
| title_fullStr | A whole-cell biosensor for the detection of gold. |
| title_full_unstemmed | A whole-cell biosensor for the detection of gold. |
| title_short | A whole-cell biosensor for the detection of gold. |
| title_sort | whole cell biosensor for the detection of gold |
| url | http://europepmc.org/articles/PMC3739760?pdf=render |
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