Jagriti Narang; Nitesh Malhotra; Chaitali Singhal; C. S. Pundir
Abstract
An electrochemical biosensor based on xanthine oxidase (XOx), titanium dioxide nanoparticles and carboxylated multi-walled carbon nanotubes (TiO2/c-MWCNT) nano-composites for sensitive detection of xanthine has been developed. TiO2/MWCNT nano-composites were used as the sensing platform in order to immobilize ...
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An electrochemical biosensor based on xanthine oxidase (XOx), titanium dioxide nanoparticles and carboxylated multi-walled carbon nanotubes (TiO2/c-MWCNT) nano-composites for sensitive detection of xanthine has been developed. TiO2/MWCNT nano-composites were used as the sensing platform in order to immobilize XOx and magnify the sensor response. FTO electrode was employed to amplify electrochemical signal in the buffer solution. Detailed morphological, electrochemical, structural and optical characterization of XOx/TiO2-NPs/c-MWCNT/FTO electrode was done using XRD, DLS, SEM, EIS, CV and shows quick response time (within 30s), linearity as 0.5- 500 µM, lower detection value of 0.05 micromolar with signal: noise ratio of 3, excellent reproducibility, high selectivity and shelf life of about 8 weeks under refrigerated conditions. The developed biosensor was further used to determine the xanthine levels in the labeo fish samples obtained from market. The accuracy of the developed biosensor was cross-checked by the customary enzymic colorimetric method (99% correlation). Thus, the existing research confirms the development of a highly sensitive, stable and a reliable bio-sensing method to detect the freshness of fish samples.
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, ...
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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), ...
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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.