Development of Vitamin B12 based disposable sensor for dissolved oxygen

We report herein a new type of Vitamin B12 based screen-printed sensor for the detection of dissolved oxygen (DO). The electrochemical behavior of Vitamin B12 modified electrode has been studied carefully, and the amperometric scheme for oxygen sensing has also been investigated. The experimental conditions were systematically optimized in acetate solution, at pH 3 and an applied potential of −0.2 V (versus Ag/AgCl with 3 M NaCl). Under the optimal conditions, the linearity of calibration is between 15 and 45 μmol L−1 (r = 0.9991) with an estimated detection limit of 9.2 μmol L−1 (S/N = 3). The reproducibility, and response time are 1.37% (R.S.D., n = 20), and 8.8 s. Further, the feasibility of using disposable strip for format DO was manifested by chronoamperometry. The results exhibited significant characteristics with a concentration range up to 0.5 mmol L−1 (r = 0.9986) at an applied potential of −0.4 V (versus Ag/AgCl with 0.1 M NaCl). A correlation study between disposable sensor strip and a commercially available DO probe has also been studied with a correlation coefficient of 0.9996. Thus, this sensor strip provides rapid, sensitive, and compatible accurate characteristics.