Browsing by Author "Manish Nath Tripathi"

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A novel approach for rapid and sensitive detection of Zika virus utilizing silver nanoislands as SERS platform
(Elsevier B.V., 2023) Manish Nath Tripathi; Poonam Jangir; Aakriti; Suyash Rai; Mayank Gangwar; Gopal Nath; Preeti S. Saxena; Anchal Srivastava
To control the spread of the disease, the Zika virus (ZIKV), a flavivirus infection spread by mosquitoes and common in across the world, needs to be accurately and promptly diagnosed. This endeavour gets challenging when early-stage illnesses have low viral loads. As a result, we have created a biosensor based on surface-enhanced Raman scattering (SERS) for the quick, accurate, and timely diagnosis of the Zika virus. In this study, a glass coverslip was coated with silver nanoislands, which were then utilized as the surface for creating the sensing platform. Silver nanoislands exhibit strong plasmonic activity and good conductive characteristics. It enhances the Raman signals as a result and gives the SERS platform an appropriate surface. The created platform has been applied to Zika virus detection. With a limit of detection (LOD) of 0.11 ng/mL, the constructed sensor exhibits a linear range from 5 ng/mL to 1000 ng/mL. Hence, even at the nanogram scale, this technique may be a major improvement over clinical diagnosis approaches for making proper, precise, and accurate Zika virus detection. © 2023 Elsevier B.V.
Exploring 32 % efficiency of eco-friendly kusachiite-based solar cells: A numerical study
(Elsevier Ltd, 2025) Sumit Choudhary; Rahutosh Ranjan; Manish Nath Tripathi; Neelabh Srivastava; Arvind Kumar Sharma; Mashamichi Yoshimura; Li Chang; Rajanish Nath Tiwari
Recently, solar cells have appeared as a promising solution to meet the increasing energy demand. However, their large-scale commercial use is limited by issues such as toxicity (Cd, Pb, etc), high manufacturing costs, lower stability, and low efficiency. In this perspective, kusachiite solar cells (KSCs) are environmentally friendly, long-term stable, and easy to manufacture. Thus, in this work, kusachiite (CuBi2O4) is used as an absorber layer, with NiO and SrTiO3 serving as the hole transport material (HTM) and an electron transport layer (ETL), respectively. The KSCs, with a structure of FTO/SrTiO3/CuBi2O4/NiO/Au, are numerically simulated. Maximum power conversion efficiency is achieved by optimizing several photovoltaic parameters, such as the thickness and doping density of the ETL, absorber, and HTM. The optimized thicknesses for the HTL, absorber layer, and ETL are 1.5 μm, 2.28 μm, and 0.02 μm, respectively. The designed KSCs exhibit an efficiency eta (η) of 31.89 %, an open-circuit voltage (Voc) of 1.31 V, a short-circuit current (Jsc) of 28.58 mA/cm2, and a fill factor (FF) of 84.99 %. © 2024
Real time SERS selective detection sensor for Galectin-1 based on RF-sputter AgNPs islands
(Elsevier B.V., 2023) Poonam Jangir; Manish Nath Tripathi; Umakant Yadav; Anchal Srivastava; Preeti Suman Saxena
Galectin −1 is a dimeric β-galactoside binding protein secreted mainly through metastatic tumor cells and plays a critical tumorigenic milieu. Galectin-1 is a potent biomarker for diagnosing pancreoductal adenocarcinoma, a type of pancreatic cancer. In this work, the surface-enhanced Raman spectroscopy (SERS) technique was studied for its use in diagnosing PDAC. A silver sputtered array platform was synthesized and coupled by NHS-EDC linker protein via sulfo–NHS–ester. To specify this platform, monoclonal Anti-GAL-1 was attached to analyze the GAL-1 antigen by surface-enhanced Raman spectroscopy (SERS). The final platform, anti-GAL-1/GAL-1/EDC-NHS/Ag, was characterized by FT-IR, AFM, XPS, and Raman spectroscopic techniques. SERS achieved good sensitivity and linearity with this optimized platform. Under optimal conditions, the fabricated platform showed good linearity in the physiological range of 1 ng/ml to 100 ng/ml with LOD 2.45 ng/ml. The modified AgNPs platform has good sensitivity, cost-effectiveness, reliability, and scalability. © 2023 Elsevier B.V.
SCAPS study on the effect of various hole transport layer on highly efficient 31.86% eco-friendly CZTS based solar cell
(Nature Research, 2023) Rahutosh Ranjan; Nikhil Anand; Manish Nath Tripathi; Neelabh Srivastava; Arvind Kumar Sharma; Masamichi Yoshimura; Li Chang; Rajanish N. Tiwari
Copper Zinc Tin Sulphide (CZTS) is a propitious semiconductor for active absorber material in thin-film solar cells (SCs). Here, SC architecture comprising FTO/ZnS/CZTS/variable HTLs/Au is discussed. Fluorine-doped tin oxide (FTO) and gold (Au) are used as front and back contacts, respectively. Zinc sulphide (ZnS) is used as an active electron transport layer (ETL), while different Cu-based materials (Cu2O, CuO, CuI, and CuSCN) are used as hole transport layers (HTL). A one-dimensional solar cell capacitance simulator (SCAPS-1D) is utilized to simulate the SC structure. Among different Cu-based HTLs, Cu2O is preferred as a potential candidate for high cell performance of CZTS-based SC. The effects of various layer parameters such as thickness, doping density, and carrier concentrations, electron affinity of HTL and absorber, respectively, are also discussed. After optimization of the device, variation of operating temperature and the effect of series and shunt resistance are also taken into consideration. The optimized results of thickness and acceptor concentration (NA) of absorber material are 1.5 µm and approx. 1.0 × 1019 cm−3, respectively. In addition, the function of HTL (with and without) in the designed SC structure is also studied. Capacitance–voltage (C–V) characteristics are also discussed to get an insight of built-in potential. We have achieved cell performances viz. efficiency = 31.86%, short circuit current density = 32.05 mA/cm2, open circuit voltage = 1.19 V, and fill factor = 83.37%. © 2023, The Author(s).
SERS based rapid and ultrasensitive detection of Japanese Encephalitis Virus
(Elsevier B.V., 2022) Manish Nath Tripathi; Kirti Singh; Umakant Yadav; Rohit Ranjan Srivastava; Mayank Gangwar; Gopal Nath; Preeti S. Saxena; Anchal Srivastava
Japanese encephalitis (JE) is a mosquito-borne flavivirus infection named Japanese Encephalitis Virus (JEV), prevalent in Asia-pacific countries, requires an accurate and rapid diagnosis to contain the outbreak of the disease. In cases of low viral load in early-stage infections, this task becomes difficult. Therefore, we have developed a surface-enhanced Raman spectroscopy (SERS) based biosensor for rapid, sensitive, and early-stage detection of JE antigen. In this work, silver nanoparticles were deposited over a glass coverslip and used as a substrate for designing the sensing platform. Silver Nanoparticles have good metallic properties and plasmon activity. Therefore, it amplifies the Raman signals and provides a suitable surface for the SERS substrate. The developed platform has been used for the detection of the Japanese encephalitis virus (JEV). The fabricated sensor shows a linear response from 5 ng/mL to 80 ng/mL with a limit of detection (LoD) of ∼7.6 ng/mL. Therefore, this method could be a significant addition to the diagnostic modalities for early, sensitive, and specific diagnoses of JE antigen even at the nanogram level. © 2022 Elsevier B.V.