PH Sensor Based On WE-QCM-D Modified With Poly(HEMA-co-MAA)

The pH sensor is an important instrument which is indispensable for chemical production and medical testing.However,as the requirements for chemical reaction control and solution property analysis continue to increase,higher requirements are put forward for the real-time performance,sensitivity,response time,biocompatibility and other indicators of pH sensors.Quartz crystal microbalance(QCM),as a new type of resonant acoustic sensor,is widely used in high-precision detection scenarios of various indicators due to its mature technology,high sensitivity,fast response,low cost,and good stability.The wireless electrodeless dissipative QCM(WE-QCM-D),as the latest detection platform of QCM,can achieve non-contact fast,stable and accurate measurement of tiny mass changes and spatial structure changes of surface attachments.In this research,with the advantages of the WE-QCM-D detection platform,a poly(HEMA-co-MAA)hydrogel sensitive film was synthesized on the surface of a quartz crystal,we manufacture a pH sensor based on WE-QCM-D modified with poly(HEMA-co-MAA).The pH sensor has been tested by the parameters of sensor calibration curve,repeatability and response time.Based on the test,the formulation of the sensitive film was optimized and analyzed,and the crystal oscillation amplitude and frequency shift response were obtained synchronously.The dynamic response interval of the optimized pH sensor is 4.0?7.0,the sensitivity of the amplitude response near pKa is 1.47V/pH,and the sensitivity of frequency response near pKa is 5548.99 Hz/pH.The response time of the sensor is 80s.In addition,the pH sensor is used for pH detection in artificial urine.For the amplitude and frequency,the relative errors of the response results compared with the measured value of the pH meter are 0.88%and 0.36%respectively.The pH test of artificial urine verifies the selectivity of the sensor and the effect of solution viscosity on the performance of the sensor.