Rajib Biswas

Tezpur University · Department of Physics

Vibrational spectroscopy plays a very vital role in the characterization of materials. It is one of the first pillars of spectroscopic tools that enable researchers to investigate the primary configuration of the object under investigation. Be it a monatomic, diatomic, or polyatomic molecule, vital rudimentary information can be accrued with the he...

This study reports synthesis of silver nanoparticles (AgNPs) in various solvent media namely, ethanol, propanol, acetone, ammonia, water, and N-Methyl-2-Pyrrolidone (NMP) by chemical and biosynthesized routes. The impact of solvent on the optical and structural characteristics of AgNPs were studied by using UV–Vis spectrophotometer and X-ray diffra...

Detection of melamine has proven to be a challenge, requiring the use of complex analytical techniques. This study introduces an innovative, straightforward one-pot technique for qualitative assessment of the milk adulterant melamine. Originally, silver nanoparticles (AgNPs) were synthesized by utilizing green tea extract, which acted as both a red...

Heavy metals are found naturally; however, anthropogenic activities such as mining, inappropriate disposal of industrial waste, and the use of pesticides and fertilizers containing heavy metals can cause their unwanted...

Mortuary/Autopsy room is a relatively high risk workplace. Infections such as Tuberculosis (TB) and HIV pose a risk to the autopsy workers. These infections pose a greater risk since many times they are not even diagnosed until the autopsy is done in the mortuary itself. In this study, we intend to analyse the prevalence of HIV in TB infected bodie...

Hydrogen Peroxide (H2O2) is a highly hazardous, toxic, and carcinogenic chemical compound utilised in various industries-based applications. Despite strict restriction, they are deliberately added to food items such as milk as preservatives to increase its shelf life. Herein, we have formulated a green rapid colorimetric nanosensor for detection of...

In recent years, there has been a lot of interest in using nanotechnology in medicine to diagnose and cure various infectious diseases. Although the precise mechanism of action is frequently challenged, many nanosized materials have been extensively explored for this purpose, using their innately unique features. Their functionality has also been e...

The prevalence of heavy metal ion contamination is increasing worldwide posing a growing threat to both ecological and human well being. In recent years, there have been significant research endeavors focused on the quantitative analysis of these heavy metal ions. There is an increasing demand for cost effective, sensitive, selective, and rapid met...

Developing cost-effective and at the same time advanced sensors has always been a challenging task for sensor designers. The choice of the sensing material determines the performance of the final sensor product as it holds paramount importance in the detection and transduction of the external stimuli in question. This fosters the sensor designers t...

This study aims to characterize the frequency magnitude distribution factor (b-value) for Nepal and its surrounding area-thereby focusing on conducting spatiotemporal and depth-wise analysis of b-value fluctuations before the November 9, 2022 earthquake of magnitude MW 6.3. Using the non-parametric Kolmogorov–Smirnov (K–S) test, earthquake events w...

As mandated by the United Nations Ad hoc Interagency Coordination Group, there is a looming prospect of acute health crises and poverty by 2030 in the absence of action against microbial resistance. Nanomaterials possess the capability to disrupt pathogenic cell membranes or induce cell death through the production of reactive oxygen species and fr...

In today’s fast-paced world, people increasingly rely on a variety of processed foods due to their busy lifestyles. The enhanced flavors, vibrant colors, and ease of accessibility at reasonable prices have made ready-to-eat foods the easiest and simplest choice to satiate hunger, especially those that undergo thermal processing. However, these food...

Resistive switching memories are among the emerging next-generation technologies that are possible candidates for in-memory and neuromorphic computing. In this report, resistive memory-switching behavior in solution-processed trans, trans-1,4-bis-(2-(2-naphthyl)-2-(butoxycarbonyl)-vinyl) benzene–PVA-composite-based aryl acrylate on an ITO-coated PE...

Quantum cryptography has been fascinating the computing world since its inception. Being governed by the principles of Quantum Mechanics, it helps us encrypt messages to prevent fraudulent trespassing as well as hacking. It also ensures fast delivery of messages to solely recipient to which it is intended. Likewise, Smart cities can bank upon crypt...

The present study conveys a new method for detecting arsenic(iii) and mercury(ii) in aqueous solution via bio-inspired gold nanoparticles. The process of synthesizing gold nanoparticles involves the utilization of the chemical reduction method. The functionalization of gold nanoparticles' surface is achieved via mango leaf extract. The as-synthesiz...

The increasing presence of heavy metal ions in aquatic environments has become a subject of escalating concern in contemporary times. Numerous human-induced activities have contributed to an elevated presence of heavy metal ions in aquatic environments, surpassing the threshold levels established by the World Health Organisation (WHO). Recently,...

The present study aims to delineate potential seismic zones within a 300 km radius centered at Tezpur in the Kopili fault region, recognizing that the region has experienced numerous devastating earthquakes due to its complex tectonic features. The high seismicity rate in the area results from these complex geological conditions. The study area, ch...

With the recent development in the field of nanotechnology, there have been significant improvements in synthesis protocols. Greener methods for synthesis are more favoured as compared to the conventional modes as the latter possesses huge number of disadvantages. In this context, our work reports biosynthesis of plasmonic silver nanoparticles (AgN...

A novel green way to synthesize plasmonic nanoparticles has been a dynamic field of research since decades as it produces ecofriendly, biocompatible, cost effective and less toxic nanoparticles. In this line, our work reports a greener route to prepare gold nanoparticles (AuNPs), by employing the bulb root segment of the banana tree. This green ext...

Vital sign detection is used across ubiquitous scenarios in medical and health settings and contact and wearable sensors have been widely deployed. Contactless detection can be achieved using camera imaging, but it is susceptible to ambient light conditions along with privacy concerns. This brief report appraises a photonic radar for non-contact vi...

The Indo-Burma area is one of the most seismically active regions because of subduction of the Indian plate under the Burmese plate. The Indo-Burma area, which is bordered by 22°–27°N and 92°-97°E, has of late witnessed multiple moderate-to-large earthquakes. Seismic hazard assessment has been performed using the well-known extreme value theory, in...

Advanced driver assistance systems has come a long way since its inception. It has evolved many folds and has now entered many mid-range vehicles. This article appraises certain features of ADAS as well as its’ pros and cons. Emphasizing the vital parts of this system, this article also highlights the challenges ahead and way forward.

Accurate measurement of temperature is very essential in laboratory scale to industrial sector. Extensive research is under way in achieving higher accuracy. In this direction, we present a comprehensive and procedural performance analysis of two hetero-core spliced system in measurement of temperature in identical domain. Employing a single mode-m...

The month of February 2023 had been a nightmare for the people of Turkiye. On 6th Feb, there was a devastating earthquake which jolted Turkiye like never before. The aftershock which followed later added more fuel to the overall damages. Till now, there has been reports several aftershocks which is believed to continue for another considerable span...

Light-intensity-modulated displacement sensors are extensively used in numerous applications. Such type of sensors operates by utilizing a pair of adjacent optical fiber—one as transmitter and the other one as receiver. Such displacement sensors have the benefits of higher sensitivity and operating range, because they can efficiently collect more l...

The proliferation of heavy metal ions in water has been a serious problem that has been escalating day by day. Rapid detection of these ions in an aqueous solution is of immense significance to keep them within permissible limits. To address the growing concentration of heavy metal ions, we report a facile and cost-effective sensing scheme. Based o...

Proliferation of heavy metal ions as aquatic pollutants has been a matter of growing concern now a days. Several anthropogenic activities have fueled higher concentration of heavy metal ions in aquatic bodies above threshold values, as set by World Health Organization. Of late, chitosan for its exquisite properties has been widely used in tackling...

Cancer is one of the dreaded diseases to which a sizeable proportion of the population succumbs every year. Despite the tremendous growth of the health sector, spanning diagnostics to treatment, early diagnosis is still in its infancy. In this regard, circulating tumour cells (CTCs) have of late grabbed the attention of researchers in the detection...

This study employed biosynthesized silver nanoparticles for colorimetric sensing of mercury ions in raw milk samples. The observed color change signifies the conversion of nanoparticles to their ionic form in presence of mercury.

This work reports sensing of heavy metal ions: arsenic (As), cadmium (Cd) and lead (Pb) by employing gold nanoparticles modified copper (Cu) electrodes.

Here, we report a Spatio-temporal analysis of the frequency magnitude distribution of earthquakes (b-value) before the 28th April 2021 (Mw 6.4) earthquake event observed in northeast India. To estimate the average b-value for the study region, a data set of 750 earthquake events with magnitude Mw≥3.9 is extracted from the homogenous part of the ear...

The electrocatalytic performance and stability of methanol oxidation reaction (MOR) and oxygen evolution reaction (OER) are mainly governed by the interfacial and surface characteristics of catalysts. Herein, a ternary nanocomposite (NiPR) of reduced graphene oxide (rGO), poly (3,4‐ethylenedioxythiophene) (PEDOT): poly (styrene sulfonic acid) (PSS)...

This paper presents the fabrication of a prototype with unique functionalities for monitoring human heart rate via simple insertion of fingertip on an infrared based sensor. The variation in the absorbance caused by the repeated pumping of oxygenated blood to various tissues within the body leads to distinct peaks and dips corresponding to the sign...

Kopili fault and its' surroundings of northeast India have remained witness to some devastating earthquakes. The complex tectonic feature of this region incurs a high seismicity rate relative to other regions. Very recently, an earthquake of magnitude 6.4 (MW) has jolted this region. Considering the persistently rising seismicity pattern of this re...

A genetic condition, termed as cystic fibrosis (CF) affecting numerous organs, including the lungs, pancreas, colon, liver, and reproductive system, is completely dormant and intrinsic. Better treatment and control of CF are facilitated by early diagnosis. With the advent of technological and healthcare developments, there has been tremendous advan...

In this study, the variation in frequency magnitude distribution factor (b‐value) before the main shock has been assessed for the 26 November 2021 Mizoram earthquake (Mw 6.1) in northeast India. The study area covering the Indo‐Burma Ranges is divided into square grids of equal dimension and spatial mapping of the b‐value for each square grid has b...

Heavy metals such as lead are gradually pervading aquatic bodies in an alarming manner. Abundance beyond a permissible level makes the aquatic bodies toxic. As such, there is a requirement of effective sensing schemes toward monitoring of the concentration of these polluting ions. Accordingly, we present here a novel photonic sensor. Using Arduino...

Generation and amplification of electronic noises are indispensable part of stochastic resonance (SR) and other molecular neuromorphic devices. Considering the paramount significance of such devices, we have endeavored to investigate the artificial noise generating and amplifying attributes of WS2 nanosheets based resistive unit. In order to realiz...

Wireless communication has grown tremendously during the last two decades. The limited coverage as well as complicacies arising because of wired networks, the industry of late favors this field immensely. As a result, there is huge upsurge is scale of wireless devices. Easy portability and absence of connecting wires enable them to be of immediate...

This work appraises a facile method for detecting lead ions in an aqueous medium. For this purpose, a D-shaped optical fiber is functionalized with gold nanoparticles with further accompaniment of aspartic acid. Subject to aggregation of gold nanoparticles as induced by Pb2+ ions, the throughput in terms of intensity via the functionalized fiber va...

Metallic nanostructures display a unique optical property termed as localized surface plasmonic resonance due to abundance of free electrons in the conduction band. When the frequency of oscillation of these electrons, induced by suitable irradiation, matches that of the electromagnetic field, it results in significant increase in absorbance and sc...

This short communication reports a unique proposition of a versatile sensing scheme—aimed at early detection of oral cancer. Based on intensity modulation, the probe can render both qualitative as well as quantitative assessments via saliva samples. It can further plausibly affirm the stage of oral cancer in the patient. With remarkable response ti...

Bioimaging methods are used to visualize biological samples and processes in real-time non-invasively. Chitosan is conjugated with other materials to form chitosan composites and is used in bioimaging due to its outstanding biodegradability and non-toxic nature. Chitosan-based nanocomposites are applied for cancer and tumour diagnosis through vario...

Flexible electronics has enabled to us reach newer heights. Now, has come the era of wearables. With the advent of advanced fabrication and integration technology, wearables have entered every domain of our life. The ease of use as well as minimal power requirement attract consumer to adopt them more and more as a part of their daily wear regime. T...

Of late, monkey pox has spread alarmingly into many countries. Originating from rain forest of African continent, it has now entered non endemic regions. Belonging to the group of pox viruses, this disease, although with less mortality, can be damaging if rising cases are not given due attention. This article overviews the origin, transmission, and...

The co-seismic deformation of the 28th April 2021 Assam earthquake with a magnitude of 6.4 has been investigated using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR). The results obtained from the PSInSAR are validated with the results of the Global Positioning System (GPS). It is observed that the co-seismic deformatio...

The increasing demand and use of plastics in our daily lives have caused an increase in microplastics (MPs) concentration in water bodies. Increasing MP in water affects aquatic life and is associated with several health issues. All sources of water whether fresh, marine, or sewage have reported the presence of various MPs. It is clear from relevan...

The co-seismic deformation of the 28th April 2021 Assam earthquake with a magnitude of 6.4 has been investigated using the Persistent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR). The results obtained from the PSInSAR are validated with the results of the Global Positioning System (GPS). It is observed that the co-seismic deformatio...

We report the findings of preliminary investigation corresponding to an optical detection technique implementing smartphone as our receiver towards quantitative assessment of heavy metal ions, namely, Cu, Zn, and Ni. Using intensity modulation, the optical responses are attained through a user-friendly app. The sensing region is made up of optical...

Chirality has always been an interesting topic in science. At present, chiral nanoparticles are in increased demand because of their unique chiroptical properties. Collective oscillations of free electrons in nanostructures result in plasmonic effects. Plasmonic has enabled the confinement of light to the nanoscales resulting in increased chiroptic...

Heavy metal ions are some of the major aquatic pollutants which are accountable for many ailments as well as undesired affects in flora and fauna. World health organization has prescribed some permissible levels for each of the heavy metal ions. The presence of ions above permissible limits results in toxicity in the aquatic bodies as well as for o...

Here in, laser power and energy dependant chemical and structural changes in WS2 nanosheets have been reported. The nanosheets were obtained through liquid phase exfoliation in N-methyl pyrrolidone (NMP). Simultaneous laser irradiation and Raman spectral analysis were performed on the nanosheets. It was observed that laser power enhancement leads t...

There is an urgent requirement of replacing the environmentally hazardous petroleum‐based plastics with sustainable and efficient starch‐based bioplastics. Development and detailed characterization of the biodegradable bioplastics from plant‐based polysaccharides such as starch is essential to reduce plastic pollution in the environment. In this re...

Remarkable photothermal properties of plasmonic nanostructures, led to the evolution of a new branch of nanoscience termed thermo-plasmonics, based on plasmonic heating of structures in nanoscale by external electromagnetic illumination. This heating generally occurs in noble metallic nanostructures, when localized surface plasmonic resonance (LSPR...

This book gives a comprehensive overview of recent advancements in both theory and practical implementation of plasmonic probes. Encompassing multiple disciplines, the field of plasmonics provides a versatile and flexible platform for nanoscale sensing and imaging. Despite being a relatively young field, plasmonic probes have come a long way, with...

On chip batteries refer to miniaturized version of powerhouse embedded on a chip. This versatile powerhouse can efficiently deliver tiny medical device without being reliant on external sources. The fabrication process of such on-chip batteries is totally different from conventional batteries. Miniaturization as well as efficient delivery of pruden...

Covid-19 has terribly shaken the whole world. The disease has spared none. Since its inception, it is observed that the virus emerges as new strains whose characteristics remain untraceable for a considerable period. These new strains are capable of baffling the health care professionals. Even the symptoms are also found to bamboozle the infected o...

In general, a majority of diseases disrupting the normal system of human are essentially caused by bacteria or viruses. They somehow enter the human body and slowly erodes the functioning of the overall system. It is no surprise that sometimes our own cells may become enemies for us. They may cause severe disruptions in the normal function of the b...

Solar cells come a long way since its invention. The stupendous growth of solar cells has opened many new avenues in many industrial sectors. Sunlight, being the primary source of solar cells is often shadowed by weather conditions such as heavy clouds, fogs, heavy rainfall etc. As such, the performance of solar cells wanes in such weather conditio...

Covid-19 has been creating a worldwide turmoil since its emergence in 2020. First detected in China, it has engulfed the entire globe. Spanning from lungs to other parts, there are reports of eyes being impacted by Covid-19. This short communication highlights the impacts of covid-19 on human eye and summarizes the observed complications caused by...

We report here the development of two computational tools PCFPS (Photonic Crystal Fiber Parameter Study) and PCFPA (Photonic Crystal Fiber Parameter Analysis), equipped with graphical user interface (GUI) for modeling of photonic crystal fiber. The tools are based on different structural parameters, and they provide characteristic analysis of the m...

We comprehensively report here a green route for synthesizing graphene oxide (GO) from waste Zn-C dry cell batteries. Here LiCl was used as electrolyte for the electrochemical synthesis of GO from graphite rods extracted from waste batteries. The satisfactory yield of 0.0305 g/h, formulated wholly through basic medium (at p H 9.36), was validated t...

Diatoms are ubiquitous in nature and they have been fascinating scientists with their unique properties. The siliceous cell capable of indulging in many exotic phenomena drive scientists to exploit its property to the fullest. Accordingly, it has been directly or indirectly engaged in many research fields encompassing biology, environmental researc...

Indoor pollution has of late risen considerably which leads to several adverse health effects. To combat this gradual rise in indoor pollution, there has been various developments. Accordingly, the present work throws light on the development of a novel sensor with the capacity for precise detection of volatile gas. The sensor comprises of clad mod...

Heavy metal toxicity has increased, necessitating quick, cheap, easy, and precise approaches for real-time evaluation. Multiple heavy metals in water will be detected using the designed four-chambered multichannel device integrated with optofluidic and electrochemical techniques.

Citrus species possess essential nutritional elements. Being rich in vitamin C, they provide considerable health benefits. Likewise, essential oils of citrus peel vary in quantity as well as quality. This concept note outlines the use ofusing a novel electrochemical biosensor for easy and fast detection of citrus metabolites which is going to, whic...

With the persistent rise of COVID-19 cases, it is imperative to have rapid assessment of infection with minimal logistics. Although different diagnostic techniques for SRAS-CoV-2 are available, there are limitations in terms of turn-around time, sensitivity, and specificity issues. In this direction, this work reports the effective exploitation of...

With the persistent rise of COVID-19 cases, it is imperative to have rapid assessment of infection with minimal logistics. Although different diagnostic techniques for SRAS-CoV-2 are available, there are limitations in terms of turn-around time, sensitivity, and specificity issues. In this direction, this work reports the effective exploitation of...

The quest for novel synthesis method of silver nanoparticles (AgNPs) is still an active field of research due to their usefulness in different levels of therapeutic and sensing applications. Owing to the better biodegradability and biocompatibility, plant extract assisted synthesis processes of AgNPs have gained considerable attention in the recent...

A comprehensive and comparative study has been performed exploiting localized surface plasmon resonance phenomenon with the purpose of sensing volatile liquids (viz. acetone, ethanol, and propanol). Accordingly, two varying geometries, namely D-type and tapered, have been used. The response has been observed by a low-cost optical detector. With uti...

With the assistance of Internet of Things (IoT), Big Data analytics has evolved tremendously. The capability of dealing and processing humongous data by high performance computing systems results in great surge in applications of Big Data analytics in various fields spanning healthcare, automobile, computing, climatology, and space communications e...

Here we present unique features of metal ion treated tungsten disulphide (WS2) nanosheets. Through chemical exfoliation of bulk WS2, multilayered WS2 nanosheets were prepared and drop casted on finger like Cu (Copper) electrodes, thereby fabricating 2D material-based sensor units. Later, I-V characteristics of the units were investigated with and w...

In this study, the crustal shear velocity structure beneath the Indo-Burma Ranges (IBR) is estimated using inversion modeling of the receiver functions computed at seismic stations operated during 2011–2018. The inversion results describe significant variations in the shear-wave velocity (Vs), velocity ratio (Vp/Vs) and crustal thickness in and aro...

The recent Assam Earthquake has been previewed in the context of the recent seismicity pertaining to Kopili Fault of northeast India. Kopili fault of northeast India is known for its active seismicity. The ground motion parameters in the context of peak ground acceleration, peak ground velocity and peak spectral acceleration stand out for their imp...

SARS-Cov-2 has emerged as one of the dreaded viruses that the world has so far faced. Ever since its outbreak, the virus has been baffling scientists with its unique inimitable pattern of mutation which leads to the beginning of several variants. Consequently, several parts of the world have gradually come under the grip of variants such as alpha,...

The Indo-Burma Ranges (IBRs) and its surrounding North-east India is one of the seismotectonically active subduction systems in the world, where the Indian Plate is subducting beneath the Sunda Plate. This has resulted in major earthquakes in the past. In this study, spectral analysis of S-wave has been used to investigate the source parameters for...

Cancer is known for higher mortality rates. If not detected in early stages, it can lead to loss of lives. Most of the therapies involved in treatment of cancer are accompanied by several undesirable effects in patients. As such, the need for a novel treatment is of immense requirement. This brief article outlines the potential possessed by magneti...

This concise report briefs about engineered inorganic nanoparticles. The principle of operation as well as reaction kinetics is also highlighted here.

Machine learning has come a long way since its inception. It has totally revolutionized the industrial scenario. For decades, there is clear evidence of usage of sophisticated digital control and monitoring systems by industrial operators. These entail multitude of sensors with defined functionalities. Through adoption of machine learning, their ha...

We present a comprehensive analysis of influence of probe geometry on responses based on localized surface plasmon resonance phenomenon. Accordingly, plasmonic responses corresponding to diverse geometries such as D-type and tapered probes are exclusively analyzed. Incorporating noble metal nanoparticles such as AuNPs and AgNPs towards facilitation...

We report here a low cost and environment friendly assessment procedure of detection of hazardous lead ions in aqueous medium. To visualize this detection, we have used biocompatible materials like chitosan, PVA and gold nanoparticles, synthesized by a green approach. For selective binding of lead ions, gold nanoparticles are functionalized with gl...