ABSTRACT
Over the past few decades, the field of organic electronics has depicted proliferated growth, due to the advantageous characteristics of organic semiconductors, such as tunability through synthetic chemistry, simplicity in processing, cost-effectiveness, and low-voltage operation, to cite a few. Organic electrochemical transistors (OECTs) have recently emerged as a highly promising technology in the area of biosensing and flexible electronics. OECT-based biosensors are capable of sensing brain activities, tissues, monitoring cells, hormones, DNAs, and glucose. Sensitivity, selectivity, and detection limit are the key parameters adopted for measuring the performance of OECT-based biosensors. This article highlights the advancements and exciting prospects of OECTs for future biosensing applications, such as cell-based biosensing, chemical sensing, DNA/ribonucleic acid (RNA) sensing, glucose sensing, immune sensing, ion sensing, and pH sensing. OECT-based biosensors outperform other conventional biosensors because of their excellent biocompatibility, high transconductance, and mixed electronic-ionic conductivity. At present, OECTs are fabricated and characterized in millimeter and micrometer dimensions, and miniaturizing their dimensions to nanoscale is the key challenge for utilizing them in the field of nanobioelectronics, nanomedicine, and nanobiosensing.
ABSTRACT
In recent years, the significance of biosensors has increased rapidly due to the growing demand for rapid detection of various biomarkers with high selectivity and sensitivity. Among different biosensors, Graphene Field Effect Transistor (Gr-FET) based biosensors has emerged as a promising device and exhibited wide range of application prospects. Gr-FET biosensors are ideal for ultra-sensitive immunological diagnosis applications as it can sense surrounding changes on their surface with low noise. Recently Gr-FET based biosensors have gained profound research interest among scientific community because of its ability in detection of SARS-CoV-2 (corona virus-2). This review article highlights the sensing performance and characteristics of different Gr-FET biosensors like DNA sensor, RNA sensor, glucose sensor, lactose sensor, protein sensor, pH sensor, various bacteria and virus detecting sensors etc.This article also critically reviews the recent progress in Gr-FET based SARS- CoV-2 covid-19 virus detection bio-sensors. © 2022 Elsevier Ltd
ABSTRACT
In recent years, the significance of biosensors has increased rapidly due to the growing demand for rapid detection of various biomarkers with high selectivity and sensitivity. Among different biosensors, Graphene Field Effect Transistor (Gr-FET) based biosensors has emerged as a promising device and exhibited wide range of application prospects. Gr-FET biosensors are ideal for ultra-sensitive immunological diagnosis applications as it can sense surrounding changes on their surface with low noise. Recently Gr-FET based biosensors have gained profound research interest among scientific community because of its ability in detection of SARS-CoV-2 (corona virus-2). This review article highlights the sensing performance and characteristics of different Gr-FET biosensors like DNA sensor, RNA sensor, glucose sensor, lactose sensor, protein sensor, pH sensor, various bacteria and virus detecting sensors etc.This article also critically reviews the recent progress in Gr-FET based SARS- CoV-2 covid-19 virus detection bio-sensors.
ABSTRACT
During the outbreak of the COVID-19 illness, mRNA (messenger RNA) injections proved to be effective vaccination. Among the presently available analytical techniques, UV/VIS spectrophotometry is a trustworthy and practical instrument that may provide information on the chemical components of the vaccine at the molecular level. In this paper, we will present a one-dimensional grating of InGaAs as a prospect grating structure for UV-VIS spectrometer that can be used for mRNA vaccine development. The main parameters and the wavelength region used in mRNA vaccine development lies in the range of 200 nm to 700 nm (UV-VIS Range). The incorporation of new materials that are excellent for cutting-edge semiconductor industry procedures for MEMS manufacture, as well as new optimal parameters, will improve the grating and spectrometer's performance which will enhance the mRNA vaccine development and manufacturing workflows enabled by UV-VIS spectroscopy. Hence we evaluated the feasibility of the materials, Si (Silicon), GaN (Gallium Nitride), InGaAs (Indium Gallium Arsenide) and InP (Indium Phosphide) as a grating material. Reflection spectrum of the proposed structure shows 48% increase compared to the grating made up of Silicon. In order to model wave propagation in one grating unit cell, electromagnetic waves frequency domain interface is used. The periodic constraints of floquet periodicity are used for simulation at both faces of the unit cell. The reflectance of grating with each material as functions of the angle of incidence was plotted. Also we evaluated the effect of grating thickness, groove density, spectral resolution and efficiency over different materials namely Si, GaN, InGaAs and InP. After optimizing geometric parameters, the designed InGaAs based grating achieved a efficiency of 87.45% and can be a reliable prospect for mRNA based vaccine development.
ABSTRACT
Sensing COVID-19, GOx (glucose oxidase enzyme) in exhaled breath condensate/saliva, bio-molecules like KIM (Kidney Injury Molecule) in human body and pH value in human body fluids have gained huge attention in the present scenario as well as in the past decade. Hence, for the first time, double channel technique in AlGaN/GaN High Electron Mobility Transistor (HEMT) is proposed and its applicability is demonstrated by biosensing application. Simulation using SILVACO Technology Computer Aided Design (TCAD) based on numerical solid state models has been extensively used for investigation and analysis. The sensitivity of double channel device is compared with single channel device and its performance is evaluated in terms of the transconductance. Unlike the single channel device, double channel device exhibited wide range of transconductance with respect to gate bias. The device recorded a sensitivity of 136%, which is 74% higher than the sensitivity of single channel device. Hence, it is inferred that the sensitivity enhances with the use of multiple channels and could be increased by increasing the number of channels. The results of this research show that the proposed sensor stands a promising candidate for future biosensing applications that demand high detection limits. © 2021