A quick biosensor for intoxicants

It costs Rs 15 and takes 15 minutes to detect the level of 15 types of intoxicants in blood. The size of a match box,a Calixarene-based metal chip developed at the Gujarat State Forensic Science University (GSFU) is a nanoparticle biosensor that can detect caffeine,codenine,morphine,marijuana,diazepam,demazepam,alprazolam and barbiturates derivates in blood and saliva,said GSFU Research and Development Director YK Agrawal,who holds a patent for the method of synthesis of Calixarene and its chloride for nanoparticles. The chip is yet to be patented.

Calixarene absorbs intoxicants,forming a complex. The complex will result in the transfer of energy in the form of specific radiation under the spectrophotometer, Professor Agrawal explained. Depending on the intensity of narcotics present in the blood,the sensors will emit colours. Some drugs are colourless,and some drugs like barbiturates emit green colour. This will be immediately detected with the help of the sensors under white light, he said,adding that the cost of the chip will not exceed Rs 15.

Calixarene,a cyclic and aromatic compound that is hydrophobic in nature,attracts positive and negative ions present in intoxicants. Calixarene nanoparticles have been put to use in cold storage of fruits and vegetables. Professor Agarwal,who has worked on Calixarene for a decade,said,As fruits are porous,they tend to petrify when exposed to the outside environment. If coated with Calixarene,its nanoparticles will occupy the pores. This will resist the reaction of the fruit with the outside environment, he said.

The instrument will not only help forensic experts detect drug usage impromptu,it can also detect poisons consumed,which can help medical experts take immediate action during an emergency. We have tested the chip on blood and saliva samples brought from different sources. A few companies have approached the varsity for the product, said Professor Agrawal,adding that it will be launched in a few months.