Kaustab Ghosh

Field-effect transistors (FETs) have become eminent electronic devices for biosensing applications owing to their high sensitivity, faster response and availability of advanced fabrication techniques for their production. The device physics of this sensor is now well understood due to the emergence of several numerical modelling and simulation papers over the years. The pace of advancement along with the knowhow of theoretical concepts proved to be highly effective in detecting deadly pathogens, especially the SARS-CoV-2 spike protein of the coronavirus with the onset of the (coronavirus disease of 2019) COVID-19 pandemic. However, the advancement in the sensing system is also accompanied by various hurdles that degrade the performance. In this review, we have explored all these challenges and how these are tackled with innovative approaches, techniques and device modifications that have also raised the detection sensitivity and specificity. The functional materials of the device are also structurally modified towards improving the surface area and minimizing power dissipation for developing miniaturized microarrays applicable in ultra large scale integration (ULSI) technology. Several theoretical models and simulations have also been carried out in this domain which have given a deeper insight on the electron transport mechanism in these devices and provided the direction for optimizing performance.

An efficient green protocol for the synthesis of luminescent biotin-conjugated CdSe quantum dots has been developed for bioimaging applications.

This study addresses the cellular uptake of nanomaterials in the field of bio-applications. In the present study, we have synthesized water-soluble lead sulfide quantum dot (PbS QD) with glutathione and 3-MPA (mercaptopropionic acid) as the stabilizing ligand using a green approach. 3-MPA-capped QDs were further modified with streptavidin and then bound to biotin because of its high conjugation efficiency. Labelling and bio-imaging of cells with these bio-conjugated QDs were evaluated. The bright red fluorescence from these types of QDs in HeLa cells makes these materials suitable for deep tissue imaging.

Glycerol–water mediated green synthesis of PbS quantum dots (QDs) is introduced utilizing distinctive precipitation strategies for bioimaging application.

Objectives: This paper entails the theoretical computation of dark current in asgrown and annealed Quantum Dot Infrared Photodetectors (QDIP). Methods/Statistical analysis: Here, non-equillibrium Green’s function was used to model the dark current characteristics in asgrown and annealed QDIPs. Post-growth thermal annealing, which reduces the traps states in the QD is also simulated using Fick’s second law of diffusion. We have developed a selfconsistent Poisson’s equation solver to compute the potential profile and quasi Fermi level at QD and at the contacts. Findings: The theoretically computed dark current obtained from our model is in good agreement with the experimental data, which validates the efficacy of our model. Our computation also predicts decrease in dark current in the QD with increase in annealing temperature at low bias voltage from0.25-1.5 volts. Application/ Improvements: Here, we have optimized the dark current for different annealing temperatures for improving the performance of QD device for infrared sensing applications