Samir Kumar

Our results demonstrate that it is possible, by means of generation of buckles on the silver nanorod (AgNR) array PDMS substrate, to enhance the Raman signal of P. aeruginosa bacteria due to the formation of high density 'hot spots' among the AgNR arrays which provides better entrapment and increases the net effective contact area of bacteria with the metal surface.

We report a facile method to fabricate novel and recyclable Ag nanoparticle decorated TiO₂nanorod array substrates using a glancing angle deposition (GLAD) technique for photocatalysis and surface enhanced Raman scattering (SERS) applications.

Surface-enhanced Raman spectroscopy (SERS) has developed as a feasible method for chemical and biological applications, unifying the precision of molecular fingerprinting with the potential sensitivity of single molecules. SERS has shown promise as a chemical and biological detection tool, but like all other methods, it has some limitations. These include brittle and fragile SERS substrates, poor adhesion of the thin film to the substrates, limited reusability of the substrates, and inhomogeneit

This book describes the different methodologies for producing and synthesizing silver nanoparticles (AgNPs) of various shapes and sizes. It also provides an in-depth understanding of the new methods for characterizing and modifying the properties of AgNPs as well as their properties and applications in various fields. This book is a useful resource for a wide range of readers, including scientists, engineers, doctoral and postdoctoral fellows, and scientific professionals working in specialized

We report a facile method to fabricate highly sensitive superhydrophobic Ag nanorods (AgNR) arrays based surface enhanced fluorescence spectroscopy (SEFS) substrates using glancing angle deposition technique at a substrate temperature of 133 K and then subsequent coating of heptadecafluoro-1-decanethiol (HDFT) molecules. The SEFS enhancement behaviour of these substrates was determined by using aqueous solution of Rhodamine 6G. The HDFT coated superhydrophobic AgNR arrays SEFS substrates exhibit

Scattering of light by molecules can be elastic, Rayleigh scattering, or inelastic, Raman scattering. In the elastic scattering, the photon’s energy and the state of the molecule after the scattering events are unchanged. Hence, Rayleigh scattered light does not contain much information on the structure of molecular states. In inelastic scattering, the frequency of monochromatic light changes upon interaction with the vibrational states, or modes, of a molecule. With the advancement in the laser

Recently, studies have been carried out to combine surface-enhanced Raman spectroscopy substrates that are based on either localized surface plasmon or surface plasmon polariton structures. By combining these two systems, the individual drawbacks of each can be overcome. However, the manufacturing methods involved so far are sophisticated, labor-intensive, expensive, and technically demanding. We propose a facile method for the fabrication of a flexible plasmonic nanoslit surface-enhanced Raman

We report the fabrication of superhydrophobic Ag nanorods substrate using glancing angle deposition (GLAD) technique. The effect of substrate temperature of Ag nanorods on contact angle was explored. The SEM images clearly confirms the difference in the morphology of the Ag nanorods grown at varying substrate temperature ranging from 313 K to 133 K which affects the roughness and the surface density of the nanostructures formed. We have controlled the size and gap of Ag nanorods to obtain higher

The plasmonic nanostructures required for the SERS are commonly in the form of solid substrates, or as colloidal solutions, both of them are not very useful to detect the biomarkers directly on human skins. Gel-based SERS substrates, into which the plasmonic nanostructures are incorporated, will be helpful for the direct collection of the biomarkers from secretions such as sweat. To elucidate these points, we studied the diffusion of Raman probe 4, 4’-Bipyridine (BPY) in the cetyltrimethylammoni

The surface-enhanced Raman scattering (SERS) electromagnetic (EM) enhancement mechanism is a two-fold enhancement process in which both the incident and scattered Raman fields are enhanced. In this letter, we present new direct evidence of the two-fold EM mechanism by using an Ag nanorod array/SiO<sub>2</sub> dielectric layer/Ag mirror multilayer thin film "local plasmon resonator". The two-fold EM enhancement mechanism of SERS was confirmed by analyzing the optical absorption and Ra

International audience

Smartphone-based point-of-care testing (POCT) is rapidly emerging as an alternative to traditional screening and laboratory testing, particularly in resource-limited settings. In this proof-of-concept study, we present a smartphone- and cloud-based artificial intelligence quantitative analysis system (SCAISY) for relative quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific IgG antibody lateral flow assays that enables rapid and accurate evaluation of test stri