Synergistic Electrochemical Amplification of Ferrocene Carboxylic Acid Nanoflowers and Cu Nanoparticles for Folic Acid Sensing

Abstract

Folic acid (FA) plays an indispensable role in human body and sometimes needs to be taken as a drug supplement, especially for pregnant women. Herein, an electrochemical FA sensor was constructed by electrodepositing Cu and ferrocene carboxylic acid (Fc(COOH)) on a glassy carbon electrode (GCE), indicating low cost, simple preparation and short time consumption. Furthermore, the field emission scanning electron microscopy illustrates that Fc(COOH) completely covering Cu nanoparticles (CuNPs) grew to be tufts of loose and porous nanoflowers in situ, which produces a large active surface area to adsorb FA. Results verify that two conjected materials exhibited a good synergistic amplification effect on FA signal. Ultimately, a great linear relationship of FA was established between 100.0 ∼ 1000.0 μM under optimized conditions by differential pulse voltammetry (DPV). The limit of detection was 33.3 μM, and the sensitivity was 0.10149 μA·μM−1·cm−2. The sensor Fc(COOH)/CuNPs/GCE showed satisfactory selectivity and stability and could be used for FA detection in FA tablets samples with an average recovery of 91.43 ∼ 100.68%, and a relative standard deviation less than 3.17%. The consistency and validity were affirmed by comparisons with an ultra-visible spectrophotometer.