Enhanced Performance of Calcium-ion Selective Electrode based on Chitosan/MXene/ZnO Modification

Calcium (Ca) is involved in the life activities of animals and plants, and also exists in the environment and human production and manufacturing processes. Therefore, this work proposes the preparation of a Ca-ion sensor. Simultaneously, MXene is an excellent electrochemical material that is expected to be applied in solid contact (SC) ion-selective electrodes (ISEs). However, MXene has high hydrophilicity, and although it is easy to uniformly form SC, it is easy to form a water layer, leading to potential drift of ISE. This study achieves the modification of MXene mixtures through the addition of additives (zinc oxide), while combining these two substances through Chitosan. The results indicates that the newly developed Ca-ISE has a potential response slope of 25.14 mV·decade−1, a detection limit of 10−6.4 M, and the SC changed from its original superhydrophilicity to hydrophobicity. This work provides certain reference value for the application of MXene in the ISE field, and the preparation of proposed Ca-ISE has promotional significance