Research Highlight

Folic acid sensor

doi:10.1038/nindia.2009.153 Published online 11 June 2009

An Indian research team has designed a polymer film-modified glassy carbon (GC) electrode that can selectively detect folic acid (FA), a B vitamin and essential compound of human blood1. Decreased concentration of FA has been linked to various diseases like gigantocytic anemia and heart disease.

The newly designed sensor could detect FA even in the presence of other chemicals such as ascorbic acid (AA) and uric acid (UA) – a trait absent in other chemical FA detectors such as mercury.

The researchers modified GC electrode with polymer film made from 5-amino-2-mercapto-1,3,4-thiadiazole. They tested its efficacy in detecting FA in human blood serum samples.

The study found that detection of very low concentration of FA is possible even in the presence of 200-fold AA and 100-fold UA. The modified electrode is more selective towards FA even in the presence of very high concentrations of AA and UA. The sensor also showed selectivity in detection of FA even in the presence of common ions and compounds such as sodium, potassium, magnesium, glucose and urea.

"The sensor detected FA even in the presence of 1000-fold excess of these interfering ions and chemicals," says lead researcher S. Abraham John from the department of chemistry of Gandhigram Rural University, Dindigul, Tamil Nadu. The sensor is easy-to-use, stable and reproducible.


  1. K, Palraj. et al. Selective electrochemical sensor for folic acid at physiological pH using ultrathin electropolymerized film of functionalized thiadiazole modified glassy carbon electrode. Biosens. Bioelectron. doi: 10.1016/j.bios.2009.05.017 (2009)