Our sensor – SAMFET-based* sensing device, which combines a high sensitivity provided by thin active layer with a selectivity provided either by reading changes of multiple parameters of the single device (“Multiparametric detection”) or simultaneous response of multiple devices with a different receptor layers (“Electronic nose”).
Multiparametric detection is based on the fact that SAMFET have several parameters (for instance, on- and –off state current, threshold voltage, charge carrier mobility, subthreshold slope), which can be changed independently during exposure into analytes.
We have demonstrated that in the case of ammonia only threshold voltage shifts, however, in the case of hydrogen sulfide charge carrier mobility decreases also. These finding allow selective detection of different analytes with single device.
Our sensors demonstrated good reproducibility of the response, operating time in continuous mode of a few days and shelf life of at least 6 months.
Combining sensor array with different receptor layers with electronic nose approach allows clear distinguishing between 4 gases (NH3, H2S, EtSH, NO2) at concentrations as low as 100ppb.