Investigation of glucose concentration in banana as a function of ripening time using Ni-Ca2CuO3 based electrochemical sensor

Chemical composition of fruits, particularly banana undergoes continuous metabolic changes as a function of ripening period and storage conditions. In this study, we report the development of a simple non-enzymatic electrochemical sensor based on Ni-Ca2CuO3 for the cost-effective and rapid determination of glucose content in banana fruits as a function of ripening period. Chronoamperometric analyses using Ni-Ca2CuO3 nanoparticles modified glassy carbon electrode (GCE) exhibited the lowest detection limit of 0.11 mu M over a wider linear range of 0.55 mu M to 23.3 mM of glucose. The potential applicability of the fabricated Ni-Ca2CuO3/GCE was evaluated by measuring glucose in green, red and yellow banana. Glucose concentrations of bananas have been determined for five successive days in order to understand the metabolic changes as a function of post-harvest storage time. The results showed that the glucose concentration increased for the first two days in the case of red and yellow banana and then decreased as the fruit ripened. Green banana showed highest glucose concentration on the first day itself and then decreased rapidly. In addition, yellow banana cooked in water has been tested separately and the result indicated that a sizeable amount of glucose is dissolved in water. These findings suggested that the fabricated non-enzymatic electrochemical sensor could be useful for monitoring glucose levels in starchy fruits and vegetable juices.