3D Bioprinted Hydrogel Sensor towards Rapid Salivary Diagnostics Based on pH Colorimetric Detection

In this paper, a novel solution of 3D bioprinted hydrogel sensor towards rapid diagnostics of saliva based on pH colorimetric detection is proposed. The hydrogel ink of unique composition of sodium alginate and polyvinylpyrrolidone was developed and printed on biocompatible substrates to achieve a repeatable and robust sensor structure. A colorimetric method was applied to visualize the hydrogel color tunability in a pH range of 5.5–7.5. The biosensor calibration curve was determined showing appropriate performance, as well as experiments with artificial saliva samples containing green tea in different proportions were conducted.