IIT Guwahati Scientists Pioneer Stable and Cost-Effective SERS Detection of Rhodamine-B

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A recent study was conducted at the Indian Institute of Technology (IIT), Guwahati that involves using surface-enhanced Raman spectroscopy. The findings were presented in a recent study (1).

The researchers at IIT collaborated on a novel semiconductor-based technique for identifying trace chemicals using surface-enhanced Raman spectroscopy (SERS) (1). This new method uses the following: a two-dimensional (2D) dendritic nanostructure of the semiconductor and palladium di-selenide (PdSe2) (1). A benefit to this newly developed method is that researchers discovered its utility as being more stable and cost-effective than previously reported methods (1). The researchers deposited small amounts of a dye called rhodamine-B onto the substrate and found that the SERS technique was highly effective at amplifying the Raman signal (1).

SERS was the best tecnique to use in this study because of its high sensitivity. It has the ability to detect extremely small amounts of various substances and is useful for detecting trace amounts of chemicals in various situations, including pollutants in water and biomarkers in blood (1). Rhodamine-B is a synthetic organic dye commonly used in various applications, such as in textile and paper industries (1). It is also used in biomedical research as a fluorescent tracer to stain cells and tissues. The dye has a pink to red color and absorbs light in the green-yellow region, making it useful in fluorescence microscopy and flow cytometry (1).

The IIT Guwahati team used a method called chemical vapor deposition (CVD) to produce the nanostructures, which were a hundred thousand times smaller than the width of a single human hair (1). The researchers found that the semiconductor-based SERS technique was more stable than metal-based methods because it exhibited no deterioration of performance over several months (1). The 2D-dendritic structures also demonstrated metal-like behavior, contributing to enhanced amplification of the Raman signal (1).

According to the researchers, the new technology can help in the development of cheaper and more reliable SERS techniques for identifying trace chemicals (1). This research addresses the growing need for reliable and cost-effective methods for detecting trace chemicals in various situations, including environmental monitoring and medical diagnostics (1).


"We have also shown by computational studies that the 2D-dendritic structures having line defects and nanopores can have metal-like behavior, which is further supported by multi-path charge transfer processes. Both of these contribute to enhanced amplification of the Raman signal," Giri said (1).

SERS works by analyzing the patterns of inelastic scattering of light (Raman scattering) by various types of materials. Gold or silver nanostructures, a hundred thousand times smaller than the width of a single human hair, were essential for using SERS effectively. When exposed to light, these nanostructures undergo a process called "electron charge oscillations," which amplifies the Raman signal (1).

Overall, the development of the new semiconductor-based SERS technique is a significant step forward in the detection of trace chemicals (1). The new technology is expected to have a significant impact on various sectors, including environmental monitoring, medical diagnostics, and forensics. The IIT Guwahati researchers' work provides a platform for future research into the development of cheaper and more reliable SERS techniques (1).


(1) DevDiscourse, IIT Guwahati researchers develop low-cost materials for spectroscopic detection of trace chemicals. (accessed 2023-04-05).