Third generation biosensing matrix based on Fe-implanted ZnO thin film

Third generation biosensor based on Fe-implanted ZnO (Fe-ZnO) thin film has been demonstrated. Implantation of Fe in rf-sputtered ZnO thin film introduces redox center along with shallow donor level and thereby enhance its electron transfer property. Glucose oxidase (GOx), chosen as model enzyme, has been immobilized on the surface of the matrix. Cyclic voltammetry and photometric assay show that the prepared bioelectrode, GOx/Fe-ZnO/ITO/Glass is sensitive to the glucose concentration with enhanced response of 0.326 μA mM−1 cm−2 and low Km of 2.76 mM. The results show promising application of Fe-implanted ZnO thin film as an attractive matrix for third generation biosensing.We are thankful to DST India and DIISR Australia for a grant under Indo-Australia strategic research initiative. Financial support from UGC is acknowledged by S.S., K.S., and V.G. S.S. is also thankful to University of Delhi for teaching assistantship. The Australian authors acknowledge financial support of the Australian National Council. Facilities at the ANU used in this work are supported by the Australian National Fabrication Facility

Mixed-Monolayer-Protected Au 25

Peer reviewe

Al and Fe co-doped transparent conducting ZnO thin film for mediator-less biosensing application

Highly c-axis oriented Al and Fe co-doped ZnO (ZAF) thin film is prepared by pulsed laser deposition. Fe introduces redox centre along with shallow donor level while Al doping enhances conductivity of ZnO, thus removing the requirement of both mediator and bottom conducting layer in bioelectrode. Model enzyme (glucose oxidase), was immobilized on surface of ZAF matrix. Cyclic voltammetry and photometric assay show that prepared bio-electrode is sensitive to glucose concentration with enhanced response of 0.18 μAmM-1cm-2 and low Km ∼ 2.01 mM. The results illustrate that ZAF is an attractive matrix for realization of miniaturized mediator-less solid state biosensor

Phylogeny and synonymous codon usage pattern of

Sub-Himalayan West Bengal is favorable for production of several fruits and vegetables. Papaya is one of the common plants cultivated in the area. Most of the papaya plants of the area are susceptible to PRSV. Coat protein genes of six Papaya ringspot virus (PRSV) isolates of the area have been sequenced following RT-PCR. Phylogenetic study of the PRSV isolates showed about 80-90% similarity with Cuban isolates also. The codon usage pattern of our isolates has also been analyzed along with several other isolates. PRSV isolates of our study showed more preference to 8 putative optimal codons. Correspondence analysis of the genes of different isolates along the first two major axes were done, as the first two axes contributed more in shaping codon usage pattern. In the phylogenetic tree, constructed by neighbour joining method our isolates clustered together with the east Indian, north Indian and Bangladeshi isolates. The diversity and codon usage pattern of the PRSV isolates of different regions were studied, where it has been observed that the codon usage pattern of PRSV isolates is influenced probably by translational selection along with mutational bias.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

An optimal method for parameter retrieval from Radio Occultation Missions

187-191Radio occultation (RO) is the Global Navigation Satellite System (GNSS) based remote sensing of Earth’s atmosphere for atmospheric parameter retrieval and total electron content (TEC) computation. Several RO missions have been launched by ISRO, viz. Meghatropiques and Oceansat-2, for atmospheric studies. Current implemented methods are able to provide the parameters only in post processed mode and hence, are available after some duration. This is due to the limitation of availability of precise satellite orbit for GNSS and LEO satellites which serves as one of the fundamental input to the process. However, a faster turnaround time is possible if the parameters are computed in near real time from the on-board solutions. This paper highlights the work that has resulted in optimizing the atmospheric parameter retrieval and TEC computation using the radio occultation technique

A Novel ZnO-Methylene Blue Nanocomposite Matrix for Biosensing Application

A novel hybrid matrix of zinc oxide-methylene blue (ZnO-MB) has been successfully developed for biosensing application. The introduction of methylene blue into the ZnO thin film leads to reduction in the charge transfer resistance and suggests an increase in the electron transfer capacity of the composite. Glucose oxidase (GOx) was chosen as the model enzyme and effectively immobilized on the surface of hybrid ZnO-MB nanocomposite matrix. Electrochemical measurements were employed to study biosensing response of the GOx/ZnO-MB/ITO bioelectrode as a function of glucose concentration. The low oxidation potential (−0.23 V) of the hybrid bioelectrode, in a mediatorless electrolyte, makes it resistant against interference from other bio-molecules. The low value of Michaelis-Menten constant (2.65 mM) indicates that immobilized GOx retains its enzymatic activity significantly on the surface of nanocomposite hybrid matrix that results in an enhanced affinity towards its substrate (glucose). The ZnO-MB nanocomposite hybrid matrix, exhibiting enhanced sensing response (0.2 μAmM−1cm−2) with long shelf-life (\u3e10 weeks), has potential for the realization of an integrated biosensing device

A Novel ZnO-Methylene Blue Nanocomposite Matrix for Biosensing Application

A novel hybrid matrix of zinc oxide-methylene blue (ZnO-MB) has been successfully developed for biosensing application. The introduction of methylene blue into the ZnO thin film leads to reduction in the charge transfer resistance and suggests an increase in the electron transfer capacity of the composite. Glucose oxidase (GOx) was chosen as the model enzyme and effectively immobilized on the surface of hybrid ZnO-MB nanocomposite matrix. Electrochemical measurements were employed to study biosensing response of the GOx/ZnO-MB/ITO bioelectrode as a function of glucose concentration. The low oxidation potential (−0.23 V) of the hybrid bioelectrode, in a mediatorless electrolyte, makes it resistant against interference from other bio-molecules. The low value of Michaelis-Menten constant (2.65 mM) indicates that immobilized GOx retains its enzymatic activity significantly on the surface of nanocomposite hybrid matrix that results in an enhanced affinity towards its substrate (glucose). The ZnO-MB nanocomposite hybrid matrix, exhibiting enhanced sensing response (0.2 μAmM−1cm−2) with long shelf-life (>10 weeks), has potential for the realization of an integrated biosensing device

A Novel ZnO-Methylene Blue Nanocomposite Matrix for Biosensing Application

A novel hybrid matrix of zinc oxide-methylene blue (ZnO-MB) has been successfully developed for biosensing application. The introduction of methylene blue into the ZnO thin film leads to reduction in the charge transfer resistance and suggests an increase in the electron transfer capacity of the composite. Glucose oxidase (GOx) was chosen as the model enzyme and effectively immobilized on the surface of hybrid ZnO-MB nanocomposite matrix. Electrochemical measurements were employed to study biosensing response of the GOx/ZnO-MB/ITO bioelectrode as a function of glucose concentration. The low oxidation potential (−0.23 V) of the hybrid bioelectrode, in a mediatorless electrolyte, makes it resistant against interference from other bio-molecules. The low value of Michaelis-Menten constant (2.65 mM) indicates that immobilized GOx retains its enzymatic activity significantly on the surface of nanocomposite hybrid matrix that results in an enhanced affinity towards its substrate (glucose). The ZnO-MB nanocomposite hybrid matrix, exhibiting enhanced sensing response (0.2 μAmM−1cm−2) with long shelf-life (\u3e10 weeks), has potential for the realization of an integrated biosensing device

Zinc oxide–potassium ferricyanide composite thin film matrix for biosensing applications

Thin film of zinc oxide–potassium ferricyanide (ZnO–KFCN) composite has been deposited on indium tin oxide (ITO) coated corning glass using pulsed laser deposition (PLD). The composite thin film electrode has been exploited for amperometric biosensing in a mediator-free electrolyte. The composite matrix has the advantages of high iso-electric point of ZnO along with enhanced electron communication due to the presence of a redox species in the matrix itself. Glucose oxidase (GOx) has been chosen as the model enzyme for studying the application of the developed matrix to biosensing. The sensing response of the bio-electrode, GOx/ZnO–KFCN/ITO/glass, towards glucose was studied using cylic voltammetry (CV) and photometric assay. The bio-electrode exhibits good linearity from 2.78 mM to 11.11 mM glucose concentration. The low value of Michaelis–Menten constant (1.69 mM) indicates an enhanced affinity of the immobilized enzyme towards its substrate. A quassireversible system is obtained with the composite matrix. The results confirm promising application of the ZnO–KFCN composite matrix for amperometric biosensing applications in a mediator-less electrolyte that could lead to the realization of an integrated lab-on-chip device