Nitesh Malhotra

Electrochemical impediometric detection of anti-HIV drug taking gold nanorods as a sensing interface.

In present work, gold nanorods were used for amplification of electrochemical sensing of anti-HIV replication drug i.e. deferiprone. Gold nanorods (nano Au) deposited onto pencil graphite electrode (PGE) has been utilized for covalent immobilization of horse radish peroxidase (HRP), via glutaraldehyde (Glu), for deferiprone detection using impedimetric technique. Gold nanorods (nano Au) prepared were characterized by TEM and XRD. The resulting nano Au sensor exhibited a good response to deferiprone with a wide linear range (0.005-1000µM) and a low detection limit 0.005µM. The biosensor also showed a short response time (within 15s). In addition, the biosensor exhibited high reproducibility, good storage stability and anti-interference ability. The applicability of the nano Au sensor is to determine deferiprone level in spiked urine and serum samples.

Point of care with micro fluidic paper based device integrated with nano zeolite–graphene oxide nanoflakes for electrochemical sensing of ketamine

The present study was aimed to develop an ultrasensitive technique for electroanalysis of ketamine; a date rape drug. It involved the fabrication of nano-hybrid based electrochemical micro fluidic paper-based analytical device (EμPADs) for electrochemical sensing of ketamine. A paper chip was developed using zeolites nanoflakes and graphene-oxide nanocrystals (Zeo-GO). EμPAD offers many advantages such as facile approach, economical and potential for commercialization. Nanocrystal modified EμPAD showed wide linear range 0.001-5nM/mL and a very low detection limit of 0.001nM/mL. The developed sensor was tested in real time samples like alcoholic and non-alcoholic drinks and found good correlation (99%). The hyphenation of EμPAD integrated with nanocrystalline Zeo-GO for detection of ketamine has immense prospective for field-testing platforms. An extensive development could be made for industrial translation of this fabricated device.

An enzyme free Vitamin C augmented sensing with different ZnO morphologies on SnO2/F transparent glass electrode: A comparative study

Three types of Zinc oxide (ZnO) nanostructures viz. ZnO nanocrystals (ZnONCs), ZnO nanoparticles (ZnONPs) and ZnO nanobelts (ZnONBs) were synthesized and characterized by UV-Vis, FTIR and SEM. A comparison of signal amplification by these ZnO nanostructures as judged by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and Linear Sweep Voltammetry (LSV) revealed that ZnONCs are better sensing interface for electrochemical detection. When these ZnO nanostructure were compared electrochemically for sensing Vitamin C, ZnONCs sensor outperformed the ZnONP and ZnONB sensor and previously reported sensors. The ZnONCs/MB/FTO electrode showed a wide linear sensing range (0.001μM to 4000μM), low detection limit (0.0001μM), a small response time (5s) and a storage stability of 6months. To the best of our knowledge, this elevated sensitivity and remarkable stability for electrochemical Vitamin C detection using ZnONCs have not been reported so far.

Hierarchical electrodeposition of methylene blue on ZnO nanocrystals thin films layered on SnO2/F electrode for in vitro sensing of anti-thalassemic drug

Zinc oxide nanocrystals-methylene blue nanocomposites were developed by electrodeposition of methylene blue onto the thin films of zinc oxide nanocrystals deposited onto SnO2/F coated glass substrates for in vitro sensing of anti-thalassemic drug i.e. deferiprone. Detailed morphological, electrochemical, structural and optical characterizations of ZnONC-MB/FTO electrode were done using XRD, SEM, EIS, FTIR, LSV, and CV and show quick response time (within 5 s), linearity as 1 × 10(-3) to 10(3) μM and shelf life of about 10 weeks under refrigerated conditions. Attempts have been made to utilize this electrode for estimation of deferiprone in urine samples. The developed sensor exhibited high reproducibility and good storage stability.

Monitoring analgesic drug using sensing method based on nanocomposite

This paper reports a rapid, reliable and sensitive electrochemical method for the determination of acetaminophen, a safe analgesic drug. Most methods currently used for therapeutic drug monitoring require a pre-treatment of the sample. Biosensors avoid this kind of drawbacks. A horseradish peroxidase (HRP) was immobilized using core–shell ZrO@Fe3O4 nanoparticles on chitosan hybrid film electrodeposited on the surface of an Au electrode. The surface functionalization of core–shell ZrO@Fe3O4NPs on a chitosan hybrid film was characterized by cyclic voltammetry (CV), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS). The experimental variables that can affect the acetaminophen amperometric response, such as the pH, temperature and applied potential, have been optimized to perform a selective determination of acetaminophen. An average limit of detection of 0.01 μM (S/N = 3) was obtained. The biosensor was finally applied to the determination of acetaminophen in complex matrices, such as pharmaceutical drugs.

Detection of alprazolam with a lab on paper economical device integrated with urchin like Ag@ Pd shell nano-hybrids

We present results of the studies relating to fabrication of a microfluidic biosensor chip based on urchin like Ag@ Pd shell nano-hybrids that is capable of sensing alprazolam through electrochemical detection. Using this chip we demonstrate, with high reliability and in a time efficient manner, the detection of alprazolam present in buffer solutions at clinically relevant concentrations. Methylene blue (MB) was also doped as redox transition substance for sensing alprazolam. Nano-hybrids modified EμPAD showed wide linear range 1-300ng/ml and low detection limit of 0.025ng/l. Low detection limit can further enhance its suitability for forensic application. Nano-hybrids modified EμPAD was also employed for determination of drug in real samples such as human urine. Reported facile lab paper approach integrated with urchin like Ag@ Pd shell nano-hybrids could be well applied for the determination of serum metabolites.

Solar tracking system using microcontroller

In this advancing era of technology we are more concerned about the advancements made in technology rather than thinking upon the alternative sources of energy. Energy costs and decreasing supplies of fossil fuels, emphasis on protecting the environment and creating sustainable forms of power have become vital, high priority projects for modern society. Since, as solar energy which is also considered a renewable form of energy can be used to offset some of the power coming from the main grid that is generated by let us say nonrenewable sources of energy. And creating these renewable sources in such a way that these provide us with the maximum efficiency is our main goal. This paper proposes a solar tracking system designed with microcontroller and ldrs that will actively track the sun and change its position accordingly to maximize the energy output. The ldrs incorporated on solar panel helps to detect sunlight which in turn moves the panel accordingly.

Multiwalled carbon nanotube wrapped nanoflake graphene composites for sensitive biosensing of leviteracetum

Current research work presents the detection of an antiepileptic drug i.e. leviteracetum by employing electrochemical impedance spectroscopy (EIS) using nanoflakes of graphene (GNF) and multiwalled carbon nanotube (MWCNT) decoratedfluorine-doped tin oxide (FTO) glass as sensing platform. This method also involved the covalent immobilized enzyme i.e. horse radish peroxidase (HRP) for LEV detection. Various stages of biosensor fabrication were characterized by TEM, XRD, SEM, EIS and CV. The sensing surface demonstrated a wide linear range (200 to 1000 μM) and a low detection limit 1 μM. The nano flakes-tubes composite based sensor showed good precision, analytical recovery and anti-interference ability which makes this sensing interface suitable for many pharmaceutical analyses. The applicability of the biosensor is to determine LEV levels in spiked serum samples.

Prussian blue nanocubes/carbon nanospheres heterostructure composite for biosensing of metformin

This paper reports the fabrication of highly sensitive metformin sensor based on Prussian blue (PB) nanocubes/carbon nanosphere (CNS) heterostructures composed of a perfect cube and spherical composite on a fluorine-doped tin oxide surface. Due to the excellent biocompatibility of PB nanocubes the PB/CNS based Mf sensor exhibited a wide linear range of 0.001–10 mM with a response duration of less than 5 s and a detection limit (based on signal to noise ratio) of 0.1 µM.

Nanocrystals of Zeolite Act as Enhanced Sensing Interface for Biosensing of Leviteracetum

In present work, nanocrystals of zeolites were employed as sensing interface for augmented electrochemical sensing of antiepileptic drug, that is, leviteracetum (LEV). Electrochemical sensing method was developed by depositing nanocrystals of zeolites and horseradish peroxidase (nanocrys zeolites-HRP) onto indium tin oxide (ITO)-coated glass surface for LEV detection. Various stages of biosensor fabrication were characterized by Transmission electron microscopy, X-ray diffraction, scanning electron microscopy, and electrochemical impedance spectroscopy. The fabricated nanocrys zeolites-HRP-modified sensor exhibited wide linear range (10-500 μM) and a low detection limit of 0.01 μM. The biosensor also showed a short response time (within 2 s). In addition, the biosensor exhibited high reproducibility, good storage stability, and anti-interference ability. The applicability of the nanocrys zeolites-HRP-modified sensor is to determine LEV level in spiked serum samples.