Science and Technology Current Affairs

CSIR-IGIB and NCDC Researchers develop DNA sensor for quick pathogen detection

Researchers form CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB) and National Centre for Disease Control (NCDC) have developed an ultrasensitive DNA chip based sensor for quick pathogen detection.

The senor can detect S. pyogenes, a bacterium which causes a wide range of diseases in about 30 minutes. The conventional method takes 18-24 hours identification of the S. pyogenes.

Key Facts

The DNA chip based sensor consists of a carbon electrode embedded with gold nanoparticles. By means of a bioinformatics study, researchers were able to design probes which are specific for S. pyogenes. The working electrode surface of the sensor is attached with several small-sized, single-stranded DNA probe specific to the pathogen.

When patients’ DNA, isolated from throat swabs are placed on the surface of the sensor, they bind to the complementary single-stranded DNA on the device leading to electrochemical change. This is measured using a differential pulse voltammetry.

Significance: The sensor is highly sensitive and could detect even 60-65 bacteria in a 6 microlitre sample. It could identify the pathogen even at very low concentrations of DNA.The sensor was found to be stable for 12 months with only 10% loss in initial current peak on storage at 4 degree C. 

S. pyogenes infections

S. pyogenes cause diseases ranging from mild skin and throat infections to life-threatening toxic shock syndrome. If not treated during early stages of the infection, it can even lead to rheumatic heart disease (heart valves damage). It affects 700 million people every year.


US Scientists develop micropropulsion system based on liquid water

Engineers from Purdue University in US have designed and tested a micropropulsion system called a Film-Evaporation MEMS Tunable Array (FEMTA) thruster that uses liquid water as the propellant for orbital maneuvering of tiny satellites called CubeSats.


CubeSats are basically miniature satellites which typically weigh around two kilograms. In the future, they have potential to carry out tasks like imaging and remote-sensing currently performed by heavier satellites which are expensive to build and launch. CubeSats at present cannot totally replace their larger counterparts as they are incapable of changing orbit or performing complex manoeuvres as they donot have a propulsion system. If CubeSats would be having system would allow such tiny satellites to correct their orbit or maintain their altitude, thereby prolonging their operating life in space before becoming space debris.

Film-Evaporation MEMS Tunable Array (FEMTA)

The FEMTA system uses an innovative design of small thrusters that deliver bursts of water vapor to manoeuvre the spacecraft into different orbits. It uses pure water as the propellant since it is safe, green, easy to use and free from the risk of contaminating sensitive instruments by the backflow from plumes as in the case of thrusters using chemical propellants.

It uses capillaries thinner than human hair through which the propellant water can flow. Small heaters located near the ends of the capillaries turn the water into vapor, which, on escaping provides the thrust. The minuscule capillaries act like valves that can be turned on and off by activating the heaters. It is compact and not power hungry. The technology is said to be similar to the inkjet printer, which uses heaters that fire dots of ink of ink at the paper.