Disposable paper sensor helps diagnose meningitis
doi:10.1038/nindia.2020.98 Published online 25 June 2020
Researchers have designed a disposable, paper-based sensor that can detect traces of meningitis-causing bacterium1. This sensor will potentially be useful for diagnosing this fatal disease at an early stage.
Among pathogens, the bacterium Neisseria meningitidis is the major cause of meningitis. It affects the membranes that surround the brain and the spinal cord. Existing techniques for detecting this bacterium are complex and expensive.
Scientists from the CSIR-Central Electrochemical Research Institute in Tamil Nadu and the Amity University in Uttar Pradesh, both in India, made the low-cost sensor by depositing specific quantum dots on a cellulose paper.
They then attached a probe DNA to the dot-attached paper. The probe DNA was added for capturing target DNA from the meningitis-causing bacterium. Such binding generates an electrical signal – a change in peak current that indicates the presence of the bacterium.
The sensor’s efficiency was tested by separately exposing it to the target DNA and a non-target DNA. On binding to the target DNA, the sensor exhibited a decrease in peak current. However, its peak current didn’t change when it bound itself to the non-target DNA.
The sensor also detected the presence of meningitis-causing bacteria in artificially prepared serum and brain-fluid samples.
Besides being stable for two weeks, the sensor displayed good sensitivity when used five times in a row. It is potentially useful for designing portable devices for onsite monitoring of meningitis, says Subbiah Alwarappan, one of the researchers.