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Low-cost graphite and double-gate FET-based label-free biosensor for dopamine sensing to detect neural diseases

Sat, 11 Jan 2025 00:00:00 GMT

Title: Low-cost graphite and double-gate FET-based label-free biosensor for dopamine sensing to detect neural diseases Authors: Deepti; Kolay, Anirban; Majumder, Subrata; Kumar, Amitesh Abstract: The manuscript proposes biosensors for detecting different concentrations of neurotransmitters named dopamine, which have a critical role in the human body's neurological, hormonal, and renal systems. In this work, the primary focus is to detect dopamine, whose disorder levels cause many neurological disabilities such as Alzheimer's and Parkinson's disease. In the present work, the simulation of two different structures has been studies: a) a graphite-based structure and b) a double gate TFET structure for detecting dopamine using TCAD Silvaco software. The proposed device utilizes a graphite-based structure with respective work functions of the used materials and studies the change in ON current (ION sensing factor is calculated for simulation study for VGS = 0.8 V). The cavity is increased to 800 µm for graphite-based biosensors for improved sensitivity. The graphite-based biosensors can detect up to 13.3 nM concentration of dopamine. Experimental electrochemical analysis results verify the proposed graphite-based biosensors' sensitivity for different dopamine concentrations. Another double gate field effect transistor (FET) biosensor has also been investigated for the detection of dopamine. The effective dielectric constant has been calculated using Bruggeman's model to check the sensitivity of double gate FET-based sensors for varying dopamine and uric acid concentrations. The sensitivity is increased with the increase of dopamine concentration percentage.

A Pilot Study on Presence of Parkinson’s Disease Risk Gene PARK7 in Population of West Bengal, India: A Preliminary Observation

Sun, 01 Jan 2023 00:00:00 GMT

Title: A Pilot Study on Presence of Parkinson’s Disease Risk Gene PARK7 in Population of West Bengal, India: A Preliminary Observation Authors: Chatterjee, Debasmita; Paira, Krishnendu; Singh, Banhishikha; Das, Satadal Abstract: ABSTRACT Introduction: The neurodegenerative Parkinson’s Disease (PD) is associated with different risk genes along with some environmental factors. Till date, there are few identified genes which play a pivotal role in the early onset of PD among the general population. Aim: To screen the presence of different risk genes of Parkinson’s disease along with associated environmental factors among randomly selected 62 urban participants. Materials and Methods: The present randomised control trial single blind pilot study was conducted in the Department of Biotechnology, Heritage Institute of Technology, Kolkata, West Bengal, India, from March 2021 to June 2021. The study participants were informed about the study and blood was collected from them. The genomic Deoxyribonucleic Acid(DNA) extraction was carried out following phenol chloroform extraction protocol and Polymerase Chain Reaction (PCR) was done with specific primers of the risk genes namely, Parkinson Disease 1 (PARK1) Alpha-synuclein (α-synuclein), Parkinson Disease 2 (PARK2) (Parkin), Parkinson Disease Protein 7 (PARK7) or DJ -1 and PINK 1. Protein Deglycase-1 (DJ-1) and PTEN Induced Kinase 1 (PINK1). The statistical analysis of the findings was done using Statistical package for the Social Sciences (SPSS) software version 21.0. Results: Out of 62 particpants, 47 were males and 15 were females and the age distribution of the participants was in between 21 years to >60 years. After obtaining specific band in agarose gel electrophoresis, 35 positive cases of PARK7 gene and one positive case of PARK2 gene were identified. Conclusion: There was a statistically significant association of different bacterial and viral infections with the PARK7 gene positive cases. PARK7 gene responsible for early onset of PD is significantly prevalent in the general population of West Bengal.

Low Sensitivity Third Order Lowpass Butterworth Filter Using CFA

Thu, 11 Nov 2010 00:00:00 GMT

Title: Low Sensitivity Third Order Lowpass Butterworth Filter Using CFA Authors: Nandy, R.; Kar, Mousiki; Das, Soumik Abstract: A third−order lowpass (LP) Butterworth filter design scheme using two CFA devices is presented. The analysis is carried out utilising the parasitic and transadmittance poles of the AD−844 type CFA elements. The circuit is practically active−insensitive with respect to the port mismatch errors (∈) of the devices. The filter characteristic had been satisfactorily verified with both PSPICE macromodel simulation and hardware circuit implementation for a frequency range 6MHz < fo< 30MHz.

Active-R Dual Input Integrator With Enhanced Time Constant Using a CDBA-Quadrature Oscillator Design

Mon, 01 Nov 2010 00:00:00 GMT

Title: Active-R Dual Input Integrator With Enhanced Time Constant Using a CDBA-Quadrature Oscillator Design Authors: Venkateswaran, P.; Das, Soumik; Nandi, Rabindra Abstract: A new dual-input integrator using a current differencing buffered amplifier (CDBA) element is presented ; the circuit needs a grounded capacitor and the time constant (τ ) has an enlargement factor being tunable by a single resistor. A sinusoid quadrature oscillator is realized thereafter with a double-integrator loop involving two such integrators. The designs are tested satisfactorily in a frequency-range of 1MHz-20MHz by both hardware implementation and PSPICE macromodel simulation.