Research Highlight

Eavesdropping on molecular cross-talk

Biplab Das

doi:10.1038/nindia.2008.261 Published online 21 August 2008

Researchers K. C. Gupta (left) & P. K. R. Kumar.

Researchers have invented a delicate sensor that detects the interaction of biomolecules. The biomolecules are adsorbed onto the nano-sized holes that dot the surface of the sensor1. The sensor could help detect a wide range of biomolecules.

The researchers coated a glass substrate with a gold layer sandwiched between two chromium layers using thermal evaporation. This was irradiated with energetic gold ions, which gave rise to latent tracks on the surface. On etching by hydrofluoric acid vapour, nanosized holes (20 nm, 50 nm and 80 nm) were created. The surface of the film was then modified with complex organic compounds including streptavidin and biotin.

On being bathed with laser light, each interaction between biomolecules gives shows a distinct change in reflectivity. The changes in the measurement of angle between incident and reflected light signal the identity of the biomolecules. "This evanescent-field-coupled (EFC) waveguide-mode sensor will facilitate detection of small molecular interactions for developing common platform for a wide range of biomolecules," says co-researcher Penmetcha Krishna Rajendra Kumar.

The authors of this work are from: Center for Applied Near Field Optics Research (CAN-FOR), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Waseda University, Shinjuku, Tokyo; Tandem Accelerator Complex, University of Tsukuba, Tsukuba, Japan; Institute for Genomics and Integrative Biology, Mall Road, Delhi University Campus, Delhi, India and Institute for Biological Resources and Functions, AIST, Tsukuba, Ibaraki, Japan.


  1. Gopinath, C. B. S. et al. Influence of Nanometric Holes on the Sensitivity of a Waveguide-Mode Sensor: Label-Free Nanosensor for the Analysis of RNA Aptamer-Ligand Interactions. Anal. Chem. (2008)  Article