Publications by authors named "Akanksha Roberts"

Japanese encephalitis (JE), a neglected tropical zoonotic disease prevalent in south-east Asian and western pacific countries, caused by the flavivirus JE virus (JEV), has a dearth of electrochemical point-of-care (PoC) diagnostic tools available to manage endemic breakouts. To overcome this, we have developed a screen-printed carbon electrode (SPCE) immunosensor for rapid PoC detection of JEV nonstructural 1 (NS1) antigen (Ag), found circulating in serum of infected individuals using a smartphone based portable "Sensit" device. The modification of SPCE surface with JEV NS1 antibody (Ab) was confirmed via observation of globular protein structures via scanning electron microscopy (SEM), increase in electrode surface hydrophilicity via contact angle measurement and decrease in current via differential pulse voltammetry (DPV).

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One of the greatest challenges faced during surgical procedures is closing and healing of wounds, which are essential in the field of orthopaedics, trauma, intensive care and general surgery. One of the main causes of death has been linked to chronic wounds, especially in immunosuppressant or diabetic patients. Due to increasing chronic wound fatality along with different pathologies associated with them, the current therapeutic methods are insufficient which has established an eminent need for innovative techniques.

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Lateral flow assays (LFAs) are one of the most economical, point-of-care (PoC) diagnostic assays that exploit the colorimetric properties of gold nanoparticles (AuNPs). Up to the best of our knowledge, no rapid antigen-based LFA exists for Japanese Encephalitis Virus (JEV) detection. Herein, we have reported a novel portable sandwich-type LFA for on-site detection of the non-structural 1 (NS1) secretory protein of JEV.

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The impact of uncontrolled antibiotic use in animals has subsequently led to emergence of antibiotic-resistant bacteria among humans due to consumption of animal by-products. Hence, to investigate antibiotic contamination in animal origin food products, we have developed a reduced graphene oxide (rGO) based immunosensor using fabricated electrode conjugated with anti-Penicillin antibody (rGO/Pen-Ab) for sensitive detection of Penicillin G. To execute this, Penicillin was first conjugated with Bovine Serum Albumin (BSA) which was confirmed via chromatographic, spectroscopic and electrophoretic-based techniques against both the in-house developed Penicillin conjugate (Pen-BSA) as well as the commercial Penicillin conjugate (Com-Pen-BSA).

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The unregulated usage of Cephalexin (CFX) in animal source food products has led to antimicrobial resistance (AMR) in humans. Graphene quantum dots (GQD) are zero-dimensional nanomaterials possessing both unique optical and electrical propertiesbased on their tuneable size that serves as an excellent signal enhancer. The fluorescence quenching and conductive properties of GQD were exploited for the detection of CFX.

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Coronavirus Disease 2019 (COVID-19) pandemic has shown the need for early diagnosis to manage infectious disease outbreaks. Here, we report a label free electrochemical Fluorine-Doped Tin Oxide (FTO) Immunosensor coupled with gold nanorods (GNRs) as an electron carrier for ultrasensitive detection of the Receptor Binding Domain (RBD) of SARS CoV-2 Spike protein. The RBD gene was cloned, and expressed in-house with confirmed molecular weight of ∼31 kDa via Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) and Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF).

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Salmonellosis is a symptomatic infection, a foodborne disease, caused by Salmonella that enters the body through the ingestion of contaminated food. In this study, a novel electrochemical biosensor integrated with gold nanorods (GNRs) was used to explore the interaction between in-house generated antibodies with Salmonella serovars. Under optimal conditions, the proposed immunosensor depicted a linear range of detection (1-1 × 10) CFU/mL witha detection limit of 105 and 23 colony forming units (CFU) ofS.

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β-Secretase1 (BACE1) catalyzes the rate-limiting step in the generation of amyloid-β peptides, that is, the principal component involved in the pathology of Alzheimer's disease (AD). Recent research studies show correlation between blood and cerebrospinal fluid (CSF) levels of BACE1 with the pathophysiology of AD. In this study, we report one-step synthesized reduced graphene oxide (rGO), activated carbodiimide chemistry, conjugated with BACE1 antibody (Ab), and immobilized on fluorine-doped tin oxide (FTO) electrodes for rapid detection of BACE1 antigen (Ag) for AD diagnosis.

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Compared with other nanomaterials, surface-modified iron oxide nanoparticles (IONPs) have gained attraction for cancer therapy applications due to its low toxicity, and long retention time. An innocuous targeting strategy was developed by generation of fluorescein isothiocyanate (FITC)-labeled peptide (growth factor domain (GFD) and somatomedin B domain (SMB)) functionalized, chitosan-coated IONPs (IONPs/C). It can be used to target urokinase plasminogen activator receptor (uPAR), which is a surface biomarker, in ovarian cancer.

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Coronavirus disease 2019 (COVID-19), which started out as an outbreak of pneumonia, has now turned into a pandemic due to its rapid transmission. Besides developing a vaccine, rapid, accurate, and cost-effective diagnosis is essential for monitoring and combating the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its related variants on time with precision and accuracy. Currently, the gold standard for detection of SARS-CoV-2 is Reverse Transcription Polymerase Chain Reaction (RT-PCR), but it lacks accuracy, is time-consuming and cumbersome, and fails to detect multi-variant forms of the virus.

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Fluorine Doped Tin Oxide (FTO) electrode was fabricated with reduced Graphene Oxide (rGO) for sensitive detection of Japanese encephalitis virus (JEV) non-structural 1 (NS1) protein. Beforehand, in-silico 3D structure, stability, and docking of recombinant JEV NS1 antigen (NS1-Ag) and antibody (Ab) was evaluated. The recombinant NS1 Ag of 42 kDa was produced in-house by successful cloning into pET-28a(+) plasmid and further expressed using BL21 Escherichia coli (E.

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Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, also known as 2019-nCov or COVID-19) outbreak has become a huge public health issue due to its rapid transmission making it a global pandemic. Here, we report fabricated fluorine doped tin oxide (FTO) electrodes/gold nanoparticles (AuNPs) complex coupled with in-house developed SARS-CoV-2 spike S1 antibody (SARS-CoV-2 Ab) to measure the response with Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV). The biophysical characterisation of FTO/AuNPs/SARS-CoV-2Ab was done via UV-Visible spectroscopy, Dynamic Light Scattering (DLS), and Fourier Transform Infrared Spectroscopy (FT-IR).

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Graphene, a two-dimensional nanomaterial, has gained immense interest in biosensing applications due to its large surface-to-volume ratio, and excellent electrical properties. Herein, a compact and user-friendly graphene field effect transistor (GraFET) based ultrasensitive biosensor has been developed for detecting Japanese Encephalitis Virus (JEV) and Avian Influenza Virus (AIV). The novel sensing platform comprised of carboxy functionalized graphene on Si/SiO substrate for covalent immobilization of monoclonal antibodies of JEV and AIV.

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Human immunodeficiency virus (HIV), a type of lentivirus (a subgroup of retrovirus), causes acquired immunodeficiency syndrome (AIDS). This pathophysiologic state destroys the immune system allowing opportunistic infections, cancer and other life-threatening diseases to thrive. Although many analytic tools including enzyme-linked immunoassay (ELISA), indirect and line immunoassay, Western blotting, radio-immunoprecipitation, nucleic acid amplification testing (NAAT) have been developed to detect HIV, recent developments in nanosensor technology have prompted its use as a novel diagnostic approach.

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Japanese Encephalitis Virus (JEV) is the most common Flavivirus based mosquito borne viral encephalitis in the world, especially in countries of South-East Asia. The conventional methods such as Enzyme-Linked Immunosorbent Assays (ELISA), Reverse Transcriptase Polymerase Chain Reaction (RT-PCR), Plaque Reduction Neutralization Test and virus isolation are still in use today but new advances are being made to develop more efficient, inexpensive, quicker, sensitive and time-saving techniques to detect JEV. Some of these include the use of immunosensors, both lateral flow based assays and electrochemical, as well as the incorporation of nanotechnology into biosensors to develop highly sensitive detection tools.

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Fluorine doped tin oxide (FTO) electrochemical immunosensor has been developed for rapid detection of urokinase type plasminogen activator receptor (uPAR) - a biomarker for cancer. uPAR is a GPI-anchored cell membrane receptor that shows increased expression in many types of human cancers which include breast, prostate, colorectal, and non-small cell lung cancer. In this study, a novel ultrasensitive FTO graphene nanosheets based electrode was used as a working probe to analyze the interaction between urokinase plasminogen activator (uPA) and monoclonal uPAR antibody (Ab).

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