A novel electrochemical paper sensor for low-cost detection of 5-methyltetrahydrofolate in egg yolk
Yanan Yu1, Dandan Sun1, Yuning Liu1
1State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; Scientific Observing and Experiment Station of Animal Genetic Resources and Nutrition in North China of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Abstract:
An electrochemical deposition method was used to fabricate a gold nanoflower (AuNF) and carbon nanoparticle (CNP) modified carbon paper (CP) sensor (AuNFs-CNPs/CP) for the low-cost detection of 5-methyltetrahydrofolate (5-mTHF) in egg yolk. AuNF morphology and structures were characterized by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), revealing nanoflower sizes in the 50 to 200 nm range. AuNFs formed on the sensor were in the Au0. We evaluated 5-mTHF assay performance using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The AuNFs-CNPs/CP sensor detected 5-mTHF concentrations in the ranges from 1 to 5 mg L-1 and 1-20 μg L-1, with an excellent limit of detection of 1 μg L-1 and good selectivity toward 5-mTHF, when compared to other potentially interfering molecules in samples. The AuNFs-CNPs/CP sensor was also used to detect 5-mTHF in folate-rich, and was found to be twice than that of ordinary egg yolk.
