VIT team aim to develop aptamer-based handheld biosensors for COVID-19 diagnosis

Aptamer-based sensing devices called aptasensors could speed up the diagnostic process of viral infections in a rapid and accurate way

Researchers at the Vellore Institute of Technology (VIT) are using aptamer-based sensor technology to develop a handheld biosensor with the potential to deliver a quick and accurate results for COVID-19 patients.

Development of a biosensor that can quickly and reliably detect the SARS-CoV-2 virus is of significant importance for containing the spread of the virus. A biosensor is a self-contained integrated device composed of a bio-recognition element that is coupled to a physico-chemical detector element or transducer which converts the recognition event into quantitative or semi-quantitative analytical information, according to the definition of International Union of Pure and Applied Chemistry.

The team, led by Dr Murugan Ramalingam, who is the principal investigator of the DST-SERB-approved project under COVID-19 scheme and Professor at the VIT, aims to use aptamers as a bio-recognition (biosensing) element and reduced graphene oxide nanomaterials as a transducer in order to design aptamer-based sensing devices called aptasensors where change in electrical conductance in the presence of SARS-CoV-2 can be measured and the sensitivity will be assessed by calculating the differences in electrical conductivity as a function of virus concentration.

The use of aptamers in biosensing platforms has recently been considered advantageous owing to their design flexibility and functional properties over antibodies in certain conditions. For example, the use of antibodies is restricted by physiological conditions when recognising the target site whereas the aptamers can easily be developed in vitro, that is, outside of human body, by systematic evolution of ligands by exponential enrichment, and it could be tailor-made to recognise a specific region of the target. It has also been reported that certain commercial antibodies unveil poor specificity and inadequate to recognise target molecules, which might lead to irreproducibility. On the other hand, certain aptamers have specific RNA sequences and express robust binding affinities for specific target molecules.

“Our team aims to develop aptasensors that can have the potential to save millions of lives by speeding up the diagnostic process of viral infections in a rapid and accurate way”, said Ramalingam. This kind of aptasensors may be of substantial benefit in the current pandemic scenario of COVID-19 as it requires small sample volume, respond within a few seconds, enable portability, high sensitivity, user-friendly and sophisticated equipment-free diagnostic, which can be used anywhere and anytime for viral screening and preventing purposes.