In this work, an all solid-state potentiometric pH sensor is developed, which employs a thin-film sputter deposited RuO2 working electrode, a polyvinylbutyral-SiO2 modified RuO2 reference electrode and 3D printed electrode housing. The developed sensor exhibits linear pH response (- 55.7 mV/pH, R2 = 0.9997) and reasonable reproducibility (hysteresis < 2 mV). Experimental results show that by using a previously developed sample-equilibration and single-point calibration protocol, an accuracy of ± 0.2 pH is achieved in a variety of sample matrices. However, by employing a matrix matched standard, bias errors are reduced and accuracy is improved to ± 0.1 pH, when compared to a commercial glass pH sensor. The developed sensor and measurement protocol is then rationalised for low throughput analysis by unskilled users.
Keywords: 3D printing; Beverage samples; Matrix matching; Ruthenium oxide; pH sensor.
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