Title: Biosensing applications of silver nanorods array

Biography:

Shashank K. Gahlaut has his expertise in fabrication of nanomaterials and their applications in biomedical science. He seeks to develop the point-of-care solutions in medical diagnosis using nanotechnology. He received his B.Sc. (Hons) in 2012 and M.Sc. degree in 2014 in Physics from Department of Physics and Astrophysics, University of Delhi, India respectively. He earned Ph.D. degree in 2015 from Department of Physics, Indian Institute of Technology Delhi. He has been an INSPIRE fellow in 2015-2020. His research interest includes gas sensors, biosensors, glancing angle deposition, chemical vapor deposition, surface enhanced Raman spectroscopy and their biomedical, energy and environmental applications.

Abstract

Silver nanostructures have been always a material of attraction due to its outstanding electrical and optical features. Here, silver nanorods (AgNRs) array fabricated on glass substrates by electron beam dynamic angle deposition, has been employed in biosensing applications. The average length and diameter of the nanorods were determined to be 900 nm and 100 nm respectively by electron microscopy. The colorimetric and water wetting properties of as-fabricated AgNRs arrays were found to be highly sensitive towards the sulfurization. In the presence of H2S gas, the as-fabricated whitish AgNRs array turns black (due to formation of black Ag2S). In addition, it also changes its water wetting property from hydrophobic (water contact angle CA=128°) to hydrophilic (CA=65°). The coproduct of the reaction; OH- ions on the AgNRs surface may found to attribute to enhance the wettability. The dual mode rapid and selective detection of H2S gas was demonstrated by using a house-made android based mobile app “Colorimetric Detector”. The performance of the sensor was investigated by its sensing ability of 5 ppm of gas with exposure time of only 30 seconds.