Sanghamitra Mandal | University of Arkansas (original) (raw)
Sanghamitra Mandal graduated with her Bachelor degree in Electrical and Electronics engineering from Uttar Pradesh Technical University, India, in 2011. She received her Master of Science degree in Semiconductor Photonics and Electronics from the University of Sheffield, England, in 2013. Her master’s thesis was on the study of the characteristics of blue gallium nitride based light emitting diodes, where a detailed experimental study on the efficiency droop phenomenon was performed. Sanghamitra is pursuing her doctoral degree in Electrical Engineering from the University of Arkansas, Fayetteville. Her research includes low cost synthesis of nanostructures, and fabrication and characterizing GaAs laser, solar cells, and electrochemical glucose sensors. She currently works at the Opto-electronics lab, where her research is to design a portable non-invasive optical sensor for glucose detection in diabetic patients.
Supervisors: Prof. Omar Manasreh
Phone: 4795951787
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Papers by Sanghamitra Mandal
The fabrication of an electrochemical sensor for glucose detection using hydrothermally grown zin... more The fabrication of an electrochemical sensor for glucose detection using hydrothermally grown zinc oxide (ZnO) nanorods is investigated. The working principle is based on the electrochemical reaction taking place between immobilized glucose oxidase adsorbed by the ZnO nanorods, and the electrolyte glucose. The synthesis of ZnO nanorods on indium tin oxide (ITO) coated glass substrate was performed using a hydrothermal sol-gel growth technique. Characterization of the ZnO nanorods was performed by using the absorption, micro-Raman, and scanning electron microscopies, and the X-ray diffraction analysis. Nafion/GOx/ZnO nanorods/ITO-coated glass substrate was used as a working electrode, while the reference electrode was a platinum plate. Amperometric response for clinical range of blood glucose concentration from 0.01-20 mM is measured at +0.8 V. The response time for the tested sensor obtained from the amperometric response curve is estimated to be less than 3 s. The analyzed sensitivity of 1151 µA/cm 2 mM-1 and the lower detection limit of 0.089 mM for the sensor were estimated from the glucose linear concentration range of 0.01 – 1.6 mM. Electrochemical characterization of the sensor was performed using the cyclic voltammetry method for a voltage range of-0.8-0.8 V at a sweep rate of 100 mV/s. Long term stability of the investigated sensor is discussed based on the study of nafion membrane scanning electron microscopy results, performed before and after the amperometric titration.
An electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized... more An electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized and tested. The ZnO nanorods are synthesized on indium titanium oxide (ITO) coated glass substrate, using the hydrothermal sol-gel technique. The working principle of the sensor under investigation is based on the electrochemical reaction taking place between cathode and anode, in the presence of an electrolyte. A platinum plate, used as the cathode and Nafion/Glucose Oxidase/ZnO nanorods/ITO-coated glass substrate used as anode, is immersed in pH 7.0 phosphate buffer solution electrolyte to test for the presence of glucose. Several amperometric tests are performed on the fabricated sensor to determine the esponse time, sensitivity and limit of detection of the sensor. A fast response time less than 3 s with a high sensitivity of 1.151 mA cm-2mM-1 and low limit of detection of 0.089 mM is reported. The glucose sensor is characterized using the cyclic voltammetry method in the range from -0.8 – 0.8 V with a voltage scan rate of 100 mV/s.
Enzymatic electrochemical sensor for glucose detection is fabricated based on hydrothermally grow... more Enzymatic electrochemical sensor for glucose detection is fabricated based on hydrothermally grown zinc oxide (ZnO) nanorods. The conception of gold (Au) nanoelectrode ensembles (NEEs) is applied to enhance the sensitivity of the electrochemical sensor under investigation. The characterization of as-synthesized ZnO nanorods on Au and indium tin oxide substrates is performed using X-ray diffraction, scanning electron microscopy, and micro- Raman spectroscopy. The current sensitivity of sensors with and without Au NEEs are computed using the cyclic voltammetry and amperometric tests executed for the glucose level ranging from 0.01 to 11.00 mM/L. Current sensitivity of 7.5 μA/mM for a linear range of glucose concentration from 0.01 to 6.5 mM is testified. Response time of 1 s and a low limit of detection of 0.065 mM is reported for the sensor based on Au NEEs. The need of ZnO nanorods in the sensor working electrode, to immobilize enzyme glucose oxidase is justified. The presence of Au NEEs boost the sensor current sensitivity by enhancing the rate of electron transfer during the electrochemical reaction.
The fabrication of an electrochemical sensor for glucose detection using hydrothermally grown zin... more The fabrication of an electrochemical sensor for glucose detection using hydrothermally grown zinc oxide (ZnO) nanorods is investigated. The working principle is based on the electrochemical reaction taking place between immobilized glucose oxidase adsorbed by the ZnO nanorods, and the electrolyte glucose. The synthesis of ZnO nanorods on indium tin oxide (ITO) coated glass substrate was performed using a hydrothermal sol-gel growth technique. Characterization of the ZnO nanorods was performed by using the absorption, micro-Raman, and scanning electron microscopies, and the X-ray diffraction analysis. Nafion/GOx/ZnO nanorods/ITO-coated glass substrate was used as a working electrode, while the reference electrode was a platinum plate. Amperometric response for clinical range of blood glucose concentration from 0.01-20 mM is measured at +0.8 V. The response time for the tested sensor obtained from the amperometric response curve is estimated to be less than 3 s. The analyzed sensitivity of 1151 µA/cm 2 mM-1 and the lower detection limit of 0.089 mM for the sensor were estimated from the glucose linear concentration range of 0.01 – 1.6 mM. Electrochemical characterization of the sensor was performed using the cyclic voltammetry method for a voltage range of-0.8-0.8 V at a sweep rate of 100 mV/s. Long term stability of the investigated sensor is discussed based on the study of nafion membrane scanning electron microscopy results, performed before and after the amperometric titration.
An electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized... more An electrochemical glucose sensor based on zinc oxide (ZnO) nanorods is fabricated, characterized and tested. The ZnO nanorods are synthesized on indium titanium oxide (ITO) coated glass substrate, using the hydrothermal sol-gel technique. The working principle of the sensor under investigation is based on the electrochemical reaction taking place between cathode and anode, in the presence of an electrolyte. A platinum plate, used as the cathode and Nafion/Glucose Oxidase/ZnO nanorods/ITO-coated glass substrate used as anode, is immersed in pH 7.0 phosphate buffer solution electrolyte to test for the presence of glucose. Several amperometric tests are performed on the fabricated sensor to determine the esponse time, sensitivity and limit of detection of the sensor. A fast response time less than 3 s with a high sensitivity of 1.151 mA cm-2mM-1 and low limit of detection of 0.089 mM is reported. The glucose sensor is characterized using the cyclic voltammetry method in the range from -0.8 – 0.8 V with a voltage scan rate of 100 mV/s.
Enzymatic electrochemical sensor for glucose detection is fabricated based on hydrothermally grow... more Enzymatic electrochemical sensor for glucose detection is fabricated based on hydrothermally grown zinc oxide (ZnO) nanorods. The conception of gold (Au) nanoelectrode ensembles (NEEs) is applied to enhance the sensitivity of the electrochemical sensor under investigation. The characterization of as-synthesized ZnO nanorods on Au and indium tin oxide substrates is performed using X-ray diffraction, scanning electron microscopy, and micro- Raman spectroscopy. The current sensitivity of sensors with and without Au NEEs are computed using the cyclic voltammetry and amperometric tests executed for the glucose level ranging from 0.01 to 11.00 mM/L. Current sensitivity of 7.5 μA/mM for a linear range of glucose concentration from 0.01 to 6.5 mM is testified. Response time of 1 s and a low limit of detection of 0.065 mM is reported for the sensor based on Au NEEs. The need of ZnO nanorods in the sensor working electrode, to immobilize enzyme glucose oxidase is justified. The presence of Au NEEs boost the sensor current sensitivity by enhancing the rate of electron transfer during the electrochemical reaction.