Synthesis of manganese oxide nanorods and its application for potassium ion sensing in water.

Potassium is an important body mineral that control the cellular and electrical functions in the body. The potassium ion concentration change in human serum causes the risk of acute cardiac arrhythmia. Hence, it is important to monitor the potassium level in drinking water/food to control the intake and prevent its effect. This paper reports synthesis of manganese oxide (MnO) nanorods using low-temperature sol-gel method for the fabrication of non-enzymatic potassium ion sensor. The detailed investigation of the as-synthesized MnO nanorods were carried out using field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The morphological and structural observations revealed that this method yield small nanorods with average length and diameters of about 210 ± 10 nm and 20 ± 3 nm, respectively. Further, as-synthesized α-MnO nanorods were used to fabricate non-enzymatic potassium ion sensor following the deposition of α-MnO nanorods on glassy carbon electrode (GCE) with the help of conductive binder. The electrochemical characterizations of fabricated non-enzymatic potassium sensor showed good sensing performance (i.e. sensitivity, selectivity, long term stability, and reproducibility). Moreover, applicability of the sensor to detect potassium ion in water samples were also demonstrated.