A disposable electrochemical sensor based on iron molybdate for the analysis of dopamine in biological samples

Abstract

Developing cost-effective approaches for the fabrication of electrochemical devices is instantly needed for transferring from basic research to point-care technology. Herein, we report an electrochemical sensing platform based on an iron molybdate (Fe₂(MoO₄)₃)-modified screen-printed carbon electrode (SPCE) for the sensitive and selective sensing of dopamine (DA). The formation and purity of Fe₂(MoO₄)₃ was characterized via multiple spectroscopic techniques. Likewise, the electrochemical performance of the Fe₂(MoO₄)₃ modified SPCE was probed via cyclic voltammetry and differential pulse voltammetry. Fe₂(MoO₄)₃/SPCE exhibited a 1.44-fold increase in electrochemical sensing activity towards DA than bare SPCE. In a range as wide as from 0.01 to 225 μM, a linear relationship is well established with the value of correlation coefficient being 0.9914. The limit of detection (S/N = 3) is well defined as 0.002 μM, which is lower than that reported previously. The fabricated Fe₂(MoO₄)₃/SPCE shows good anti-interference ability towards DA detection in the presence of numerous co-interfering compounds at a higher level. Moreover, a biological analysis indicated that spiked DA can be determined accurately by Fe₂(MoO₄)₃ modified SPCE with the recovery rate in the range of 99.30–99.80% in human serum samples. Based on the above-mentioned results, the proposed electrochemical sensor has great potential in the fields of biological detection.