doi:10.1038/nindia.2014.141 Published online 27 October 2014
Researchers have developed a sensitive, fluorescent sensor that can detect minute traces of iron ions in normal and cancerous liver cells1. The sensor is based on a fluorescent organic compound and is potentially useful for diagnosing diseases linked to abnormal iron levels in biological cells.
Metal ions such as iron play vital roles in biochemical processes at the cellular level. A deficiency or excess of iron can cause various diseases. However, existing iron sensors use rhodamine dyes, which are harmful to humans and animals. The researchers fabricated an effective and ecofriendly iron sensor by using a fluorescent organic compound known as benzo-thiazolo-pyrimidine-1. They then tested the efficacy of the sensor in detecting iron ions by exposing it to different aqueous solutions containing iron and other metal ions. They carried out these measurements under ultraviolet and visible light.
Under ultraviolet light, the sensor exhibited yellow fluorescence in the presence of solution containing iron ions, but did not show such fluorescence when exposed to solutions containing other metal ions such as potassium, copper, magnesium and manganese.
Under visible light, the sensor showed a ten-fold increase in fluorescence when exposed to solution containing iron ions. The sensor selectively detected iron ions even in the presence interfering metal ions usually found in biological fluids. The researchers found that by monitoring the fluorescence, the sensor could detect iron ions in normal and cancerous liver cells.
“This sensor could easily permeate cell membranes and is capable of detecting iron ions down to 0.74 nanomole,” says Umesh Patil, a senior author of the study.
1. Nandre, J. et al. A novel fluorescent "turn-on" chemosensor for nanomolar detection of Fe(III) from aqueous solution and its application in living cells imaging. Biosens. Bioelectron. 61, 612-617 (2014)