Nidhi Chauhan; Utkarsh Jain
Abstract
The glucose level measurement in the blood of diabetic patients without significant variations is important. The level of glycated hemoglobin (HbA1c) in the blood provides an authentic tool for glucose level measurement. In our study, a biosensing system established on properly aligned single-crystal ...
Read More
The glucose level measurement in the blood of diabetic patients without significant variations is important. The level of glycated hemoglobin (HbA1c) in the blood provides an authentic tool for glucose level measurement. In our study, a biosensing system established on properly aligned single-crystal zinc oxide (ZnO) nanorods structures grown on indium-tin oxide coated glass plate (ITO) electrode. ZnO nanorods were immobilized with fructosyl amino-acid oxidase (FAO) enzyme through physical adsorption integrated with cross linking molecules N-5-azido-2-nitro-benzoyloxysuccinimide (ANB-NOS). Whole blood samples were first hemolyzed & then properly digested with protease prior to measuring the HbA1c through the sensor. This enzyme biosensor reported an optimum response at +0.2 V. This biosensor displayed a significant sensitivity and detection limit (0.1μM), fast response time (4s) and wide linear range (from 0.1 to 2000 μM). The enzyme/working electrode is stable for about 4 months, when kept at 4 oC. This recommended biosensor method may apply for detecting HbA1c in blood samples obtained from apparently healthy as well as diabetic patients.
Jagriti Narang; Nidhi Chauhan; Ashish Mathur; Vivek Chaturvedi; C.S. Pundir
Abstract
In present work, we employed gold nanorods for electrochemical sensing of bilirubin. A new method is developed by using covalently immobilized bilirubin oxidase (BOx) on gold nanorods and employed gold microelectrode. The sensing interface materials were characterized by dynamic light scattering (DLS), ...
Read More
In present work, we employed gold nanorods for electrochemical sensing of bilirubin. A new method is developed by using covalently immobilized bilirubin oxidase (BOx) on gold nanorods and employed gold microelectrode. The sensing interface materials were characterized by dynamic light scattering (DLS), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The optimum response was observed at pH 7 and 35 ºC. The linear working range of the biosensor is 0.01 -500 µM. Fabricated sensing technology showed good evaluation parameters like precision (2.2 % and 3.2 %) and analytical recovery (98.2 % and 97.4 %). Bilirubin biosensor can be employed for early detection of bilirubin in blood serum to check jaundice,hyperbilirubinia and physiologic jaundice in infants.
Jagriti Narang; Utkarsh Jain; Nitesh Malhotra; Sandeep Singh; Nidhi Chauhan
Abstract
An amperometric lysine biosensor was fabricated by immobilizing lysine oxidase onto core shell magnetic nanoparticles (Core–shell MNPs)/multiwalled carbon nanotube (MWCNT) layer deposited on Au electrode via carbodiimide linkage. Transmission electron microscopy (TEM) for core–shell MNPs, ...
Read More
An amperometric lysine biosensor was fabricated by immobilizing lysine oxidase onto core shell magnetic nanoparticles (Core–shell MNPs)/multiwalled carbon nanotube (MWCNT) layer deposited on Au electrode via carbodiimide linkage. Transmission electron microscopy (TEM) for core–shell MNPs, scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and Fourier transform impedance spectroscopy (FTIR) studies were used to characterize the modified electrode. Sensor showed optimal response within 2s at 30ºC in 0.05 M sodium phosphate buffer pH 6.0 when polarized at +0.2 V vs. Ag/AgCl. Linear working range of the biosensor was determined by 0.05 -700 μM with a detection limit of 0.05 μM. A good correlation (r = 0.98) was obtained between serum lysine levels measured by the standard HPLC method (y) and the present method (x). A number of serum substances had practically no interference. The sensor was used in 150 assays and had a storage life of 180 days at 4 o C. This nanohybrid biosensor will be useful for detection of lysine in food and pharmaceutical industries.
Jagriti Narang; Nitesh Malhotra; Nidhi Chauhan; Sandeep Singh; Gajendra Singh; C.S. Pundir
Abstract
A polyphenol oxidase (PPO) was immobilized by employing magnetic nanoparticles-zinc oxide/zinc hexacyanoferrate (Fe3O4NP-ZnO/ZnHCF) hybrid film electrodeposited on the surface of Pt electrode. The surface functionalization of Fe3O4NP-ZnO/ZnHCF hybrid film was characterized by cyclic voltammetry (CV), ...
Read More
A polyphenol oxidase (PPO) was immobilized by employing magnetic nanoparticles-zinc oxide/zinc hexacyanoferrate (Fe3O4NP-ZnO/ZnHCF) hybrid film electrodeposited on the surface of Pt electrode. The surface functionalization of Fe3O4NP-ZnO/ZnHCF hybrid film was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), atomic force microscopy (AFM) and electrochemical impedance spectroscopy (EIS) before and after immobilization of PPO. The biosensor exhibited optimum response within 4s at pH 7.0 and 35°C and linearity in the range 0.04 to 10000 μM for acetaminophen with a detection limit of 0.04 μM (S/N=3). Accuracy of the proposed sensor was found to be 99%. The use of Fe3O4NP/ZnO/ZnOHCF for construction of amperometric acetaminophen biosensor has resulted into relatively rapid response, higher sensitivity, broad linear range, lower detection limit, good reproducibility and long term stability of this biosensor. This sensing interface provides better avenue for the fabrication of various sensor.