Context: Recently, the National Centre for Polar and Ocean Research and the Goa University have successfully synthesized gold nanoparticles (GNPs) using psychrotolerant Antarctic bacteria through a non-toxic, low-cost, and eco-friendly way.
Key Points

• The study has established that 20-30-nm-sized spherical-shaped GNPs could be synthesized in a controlled environment.
• These GNPs can be used as a composite therapeutic agent in clinical trials, especially in anti-cancer, anti-viral, anti-diabetic, and cholesterol-lowering drugs.
• The NCPOR-GU study revealed the genotoxic effect of GNPs on a sulphate reducing bacteria (SRB).
• The GNPs displayed enough anti-bacterial properties by inhibiting the growth of SRB and its sulphide production by damaging the genetic information of the DNA of the bacterial cell.
• Genotoxicity describes the property of a chemical agent that is capable of damaging the genetic information of DNA and thus causing a mutation of the cell, which can lead to cancer.

About Gold Nanoparticles (GNPs)

• Gold nanoparticles (AuNPs) are small gold particles with a diameter of 1 to 100 nm which, once dispersed in water, are also known as colloidal gold.
• GNPs are found to have greater solar radiation absorbing ability than the conventional bulk gold, which makes them a better candidate for use in the photovoltaic cell manufacturing industry.
• GNPs have unique optical properties too. For example, particles above 100 nm show blue or violet colour in water, while the colour becomes wine red in 100 nm gold colloidal particles. They can thus be used in therapeutic imaging.
• GNPs also have unique physicochemical properties. Their biocompatibility, high surface area, stability, and nontoxicity make them suitable for various applications in therapeutic use including detection and diagnosis of diseases, bio-labelling, and targeted drug delivery.
• As nano-carriers, GNPs are capable of transferring various drugs made out of peptides, proteins, plasmid DNAs, small interfering RNAs, and chemotherapeutic agents to target diseased cells of the human body.
• GNPs are also found to be useful in the electronics industry.
• Scientists have constructed a transistor known as NOMFET (Nanoparticle Organic Memory Field-Effect Transistor) by embedding GNPs in a porous manganese oxide as a room temperature catalyst to break down volatile organic compounds in air and combining GNPs with organic molecules.
• NOMFETs can mimic the feature of the human synapse known as plasticity, or the variation of the speed and strength of the signal going from neuron to neuron.
• These novel transistors can now facilitate better recreation of certain types of human cognitive processes, such as recognition and image processing and have their application in artificial intelligence.