Recently, global traceability and measurements of mercury have been addressed with a network approach using automated and/or semi-automated systems for its sampling and detection in air and/or wet deposition. Based on the commonly used analytical procedures for the determination of mercury in precipitation within the GMOS global network, it has been highlighted the disadvantage of more than 40 monitoring sites. These latter require significant running costs for sampling and shipping samples to the reference laboratories, especially in remote regions such as Antarctica or in underdeveloped areas that do not have basic infrastructures. The sustainability of global scale monitoring networks for measuring mercury in air or precipitation samples depends on the development of advanced online (bio)sensors capable to quantify total mercury or even better speciated mercury concentrations. These advanced sensors should be robust, traceable and do not require gas carrier, significant energy supply and highly qualified technical expertise. Taking into consideration all the above our goal is to present preliminary results on a sensor based on electrochemical impedance spectroscopy (EIS) for mercury speciation in air or wet deposition Hg(I) and Hg(II) from wet deposition are electrochemically reduced to Hg(0) and deposed on a gold ?-electrode. Similarly Hg(0) from air spontaneously reacts on a gold electrode to create amalgam. Hg(II) selectively reacts with oligonucleotides (12 bases) made of thymine. EIS, a powerful and sensitive technique, allows querying the electrode surface. After EIS measurement Hg(0) can be easily removed from the gold surface by electrochemical oxidation and Hg(II) with imidazole . Minimal volumes and surfaces play a role in sensor performances. Relevance Preliminary results about a cheap and low-power electrochemical sensor for Hg speciation in air and wet deposition based on gold ?-electrodes and EIS are reported. The sensor shows high sensitivity, L.o.d.= 0.06 ppq, L.o.q.=0.10 ppq and a sampling rate from 3 to 12 samples/h. Complete renewal of the gold surface has been observed simply by electrochemical potential.
Highly sensitive impedimetric biosensors for Mercury in air or wet depositions
Pilloton R
2015
Abstract
Recently, global traceability and measurements of mercury have been addressed with a network approach using automated and/or semi-automated systems for its sampling and detection in air and/or wet deposition. Based on the commonly used analytical procedures for the determination of mercury in precipitation within the GMOS global network, it has been highlighted the disadvantage of more than 40 monitoring sites. These latter require significant running costs for sampling and shipping samples to the reference laboratories, especially in remote regions such as Antarctica or in underdeveloped areas that do not have basic infrastructures. The sustainability of global scale monitoring networks for measuring mercury in air or precipitation samples depends on the development of advanced online (bio)sensors capable to quantify total mercury or even better speciated mercury concentrations. These advanced sensors should be robust, traceable and do not require gas carrier, significant energy supply and highly qualified technical expertise. Taking into consideration all the above our goal is to present preliminary results on a sensor based on electrochemical impedance spectroscopy (EIS) for mercury speciation in air or wet deposition Hg(I) and Hg(II) from wet deposition are electrochemically reduced to Hg(0) and deposed on a gold ?-electrode. Similarly Hg(0) from air spontaneously reacts on a gold electrode to create amalgam. Hg(II) selectively reacts with oligonucleotides (12 bases) made of thymine. EIS, a powerful and sensitive technique, allows querying the electrode surface. After EIS measurement Hg(0) can be easily removed from the gold surface by electrochemical oxidation and Hg(II) with imidazole . Minimal volumes and surfaces play a role in sensor performances. Relevance Preliminary results about a cheap and low-power electrochemical sensor for Hg speciation in air and wet deposition based on gold ?-electrodes and EIS are reported. The sensor shows high sensitivity, L.o.d.= 0.06 ppq, L.o.q.=0.10 ppq and a sampling rate from 3 to 12 samples/h. Complete renewal of the gold surface has been observed simply by electrochemical potential.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
