Zimmer and Peacock introduce a pH sensor, based on a format that makes the sensors suitable as single use or for continuous monitoring applications.
In the adjacent image we show a comparison between a Zp solid state pH sensor without a chloride resilient electrode and with a chloride resilient electrode, you can see that the pH electrode with a chloride resilient electrode is more invariable with as the chloride is increased, as we would expect.
In the Figure below you are looking at the raw data gathered on a ZP pH sensor, the scientist was testing eight pH electrodes in parallel. The sensors were initially in a solution of pH 7.39, the pH was then changed to pH 9.95, next the pH was changed to 3.75 before finally changed back to 7.39.
In the chart below we have taken the raw data from the experiment and plotted the signal (milliVolts, mV) versus the pH. From that we have calculated our sensitivity of 51 mV/pH/.
In the figure below we have the data for the continuous operation of a ZP pH sensor for 27 minutes. The scientist changed the pH over the 27 minutes by the addition of acid and base so one can see the sensor responding (y axis mV). The data suggests the pH sensor can be used either a s a discreet measurement sensor, i.e measure a drop of blood and then disposed of, or as a continuous sensor in a flowing liquid etc.
In the figure below we test a pH sensor that has been in storage at room temperature for 9 months. The sensor has no liquid on board so it is immediately ready to go and the fact that the pH sensor is entirely solid state means the pH sensor has excellent shelf life.
As a side note we have a 86 microV per degree temperature coefficient.
The beautiful aspect of the ZP's solid state pH sensors is how robust they are. These pH sensors are made from inorganic materials with no liquids and so they last ages with no careful storage, see below.
ZP has tested the sensors in two different matrices below.
We are also providing the pH sensors in two additional micro-capillary formats, where the pH sensor is housed within a microfluidic cavity, the cavity is designed so that solution is drawn automatically into the sensing area, see adjacent video.
Below we are offering the pH sensors in this capillary format with and without a filter paper. The filter paper which is situated within the capillary is designed to filter particles and materials from the sample matrix.
pH sensors for applications where the sensor is disposable or where continuous measurement is required. This sensor has capillary fill, but no filter.
pH sensors for applications where the sensor is disposable or where continuous measurement is required. This sensor has capillary fill and filter in place.