ORCID Profile
0000-0003-0877-1275
Current Organisations
Tufts University
,
Shree Guru Gobind Singh Tricentenary University Faculty of Medicine and Health Sciences
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Publisher: IEEE
Date: 30-10-2022
Publisher: Elsevier BV
Date: 07-2021
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 08-2023
Publisher: American Chemical Society (ACS)
Date: 18-05-2020
Publisher: Elsevier BV
Date: 06-2017
Publisher: Elsevier BV
Date: 09-2016
DOI: 10.1016/J.TALANTA.2016.05.043
Abstract: The discovery of in-vitro systematic evolution of ligands by exponential enrichment (SELEX) process has considerably broaden the utility of aptamer as bio-recognition element, providing the high binding affinity and specificity against the target analytes. Recent research has focused on the development of structure switching signaling aptamer assay, transducing the aptamer- target recognition event into an easily detectable signal. In this paper, we demonstrate the development of structure switching aptamer assay for determination of aflatoxin M1 (AFM1) employing the quenching-dequenching mechanism. Hybridization of fluorescein labelled anti-AFM1 aptamer (F-aptamer) with TAMRA labelled complementary sequences (Q-aptamer) brings the fluorophore and the quencher into close proximity, which results in maximum fluorescence quenching. On addition of AFM1, the target induced conformational formation of antiparallel G-quadruplex aptamer-AFM1 complex results in fluorescence recovery. Under optimized experimental conditions, the developed method showed the good linearity with limit of detection (LOD) at 5.0ngkg(-1) for AFM1. The specificity of the sensing platform was carefully investigated against aflatoxin B1 (AFB1) and ochratoxin A (OTA). The developed assay platform showed the high specificity towards AFM1. The practical application of the developed aptamer assay was verified for detection of AFM1 in spiked milk s les. Good recoveries were obtained in the range from 94.40% to 95.28% (n=3) from AFM1 spiked milk s le.
Publisher: Springer Science and Business Media LLC
Date: 12-09-2023
Publisher: MDPI AG
Date: 26-12-2016
Publisher: MDPI AG
Date: 22-09-2015
Publisher: MDPI AG
Date: 02-2021
DOI: 10.3390/MOLECULES26030748
Abstract: With the increasing prevalence of growing population, aging and chronic diseases continuously rising healthcare costs, the healthcare system is undergoing a vital transformation from the traditional hospital-centered system to an in idual-centered system. Since the 20th century, wearable sensors are becoming widespread in healthcare and biomedical monitoring systems, empowering continuous measurement of critical biomarkers for monitoring of the diseased condition and health, medical diagnostics and evaluation in biological fluids like saliva, blood, and sweat. Over the past few decades, the developments have been focused on electrochemical and optical biosensors, along with advances with the non-invasive monitoring of biomarkers, bacteria and hormones, etc. Wearable devices have evolved gradually with a mix of multiplexed biosensing, microfluidic s ling and transport systems integrated with flexible materials and body attachments for improved wearability and simplicity. These wearables hold promise and are capable of a higher understanding of the correlations between analyte concentrations within the blood or non-invasive biofluids and feedback to the patient, which is significantly important in timely diagnosis, treatment, and control of medical conditions. However, cohort validation studies and performance evaluation of wearable biosensors are needed to underpin their clinical acceptance. In the present review, we discuss the importance, features, types of wearables, challenges and applications of wearable devices for biological fluids for the prevention of diseased conditions and real-time monitoring of human health. Herein, we summarize the various wearable devices that are developed for healthcare monitoring and their future potential has been discussed in detail.
Publisher: CRC Press
Date: 27-05-2022
Publisher: Springer Science and Business Media LLC
Date: 07-06-2014
DOI: 10.1007/S12010-014-0985-0
Abstract: There is a need for analytical methods capable of monitoring urea levels in urine for patients under clinical monitoring to appraise renal function. Herein, we present a practical method to quantify levels of urea in human urine s les using flow injection analysis-enzyme thermistor (FIA-ET) biosensor. The biosensor comprises a covalently immobilized enzyme urease (Jack bean) on aminated silica support, which selectively hydrolyzes the urea present in the s le. Under optimized conditions, the developed biosensor showed a linear response in the range of 10-1,000 mM, R (2) = 0.99, and response time of 90 s in 100 mM phosphate buffer (PB) (flow rate of 0.5 mL/min, s le volume of 0.1 mL, and pH 7.2). The urea-spiked human urine s les showed minimal matrix interference in the range of 10-1,000 mM. Recoveries were obtained (92.26-99.80 %) in the spiked urine s les. The reliability and reproducibility of the developed biosensor were found satisfactory with percent relative standard deviation (% RSD) = 0.741. The developed biosensor showed excellent operational stability up to 30 weeks with 20 % loss in original response when used continuously at room temperature. These results indicate that the developed biosensor could be very effective to detect low and high levels of urea in urine s les.
Publisher: MDPI AG
Date: 11-05-2018
Publisher: Elsevier BV
Date: 08-2020
Publisher: Elsevier BV
Date: 09-2016
Abstract: In this study, a simple TAMRA (tetramethyl-6-carboxyrhodamine) quenching-based aptasensing platform was designed for the detection of aflatoxin B1 (AFB1). Here, we compared the analytical performance of two aptamer sequences: seqA and seqB. The AFB1 detection was based on the interactions of FAM (carboxyfluorescein)-labeled aptamer with TAMRA-labeled DNA complementary strand in the presence and absence of target analyte. Under optimized experimental conditions, TAMRA-labeled strand quenched the fluorescence response of FAM-labeled aptamer due to the noncovalent interaction between the two DNA strands. The binding of AFB1 induced the complex formation and weakened the interaction between FAM-labeled aptamer and TAMRA-labeled complementary strand, resulting in the fluorescence recovery. By using this principle concept, an assay was constructed for the detection of AFB1. The method exhibited good sensitivity, good selectivity with a limit of detection of 0.2 ng ml(-1), and a wide linear range from 0.25 to 32 ng ml(-1). For real s le application, the aptasensors were tested in beer and wine s les, with good recovery rates obtained for AFB1 detection.
Publisher: Bentham Science Publishers Ltd.
Date: 04-02-2019
DOI: 10.2174/2215083805666190617110019
Abstract: The continuous attempt of drug discovery and search for a potential drug molecules with promising pharmacological activities is always of immense interest. Most of those chemical compounds having active pharmacological effects contain heterocyclic nucleus or compounds. Heterocyclic compounds clutch a particular place among pharmaceutically active natural and synthetic compounds. The ability to serve both as biomimetics and reactive pharmacophores of the heterocyclic nucleus is incredible and principally contributed to their unique value as traditional key elements of many drugs. These heterocyclic nuclei offer a huge area for new lead molecules in drug discovery and for the generation of activity relationships with biological targets to enhance their pharmacological effects. In the heterocyclic nucleus, the hydrogen bond acceptors and donors arranged in a manner of a semi-rigid skeleton in heterocyclic rings and therefore can present a varied display of significant pharmacophores. Lead identification and optimization of a probable drug target can be achieved by the generation of chemically erse heterocyclic pharmacophores with different groups or substituents. Herein, an attempt is made to review and summarize the naturally occurring carbazole containing alkaloids obtained from Murraya, Causena and Glycosmis species and their potential towards anticancer activity. Carbazole is a tricyclic heterocyclic molecule and an integral part of naturally occurring alkaloids possessing various potential biological activities such as anticancer, antimicrobial and antiviral. Due to the high binding affinity of carbazole towards nucleic acid/ receptor and mimicking their biological activity, carbazole derived alkaloids exhibit the potential cytotoxic effect.
Publisher: Bentham Science Publishers Ltd.
Date: 04-02-2021
Publisher: Bentham Science Publishers Ltd.
Date: 2021
DOI: 10.2174/1381612826666201118113311
Abstract: Since the discovery of DNA intercalating agents (by Lerman, 1961), a growing number of organic, inorganic, and metallic compounds have been developed to treat life-threatening microbial infections and cancers. Fused-heterocycles are amongst the most important group of compounds that have the ability to interact with DNA. DNA intercalators possess a planar aromatic ring structure that inserts itself between the base pairs of nucleic acids. Once inserted, the aromatic structure makes van der Waals interactions and hydrogen-bonding interactions with the base pairs. The DNA intercalator may also contain an ionizable group that can form ionic interactions with the negatively charged phosphate backbone. After the intercalation, other cellular processes could take place, leading ultimately to cell death. The heterocyclic nucleus present in the DNA intercalators can be considered as a pharmacophore that plays an instrumental role in dictating the affinity and selectivity exhibited by these compounds. In this work, we have carried out a revision of small organic molecules that bind to the DNA molecule via intercalation and cleaving and exert their antitumor activity. A general overview of the most recent results in this area, paying particular attention to compounds that are currently under clinical trials, is provided. Advancement in spectroscopic techniques studying DNA interaction can be examined in-depth, yielding important information on structure-activity relationships. In this comprehensive review, we have focused on the introduction to fused heterocyclic agents with DNA interacting features, from medicinal point of view. The structure-activity relationships points, cytotoxicity data, and binding data and future perspectives of medicinal compounds have been discussed in detail.
Publisher: Biomedical Research Network, LLC
Date: 30-10-2018
Publisher: IEEE
Date: 30-10-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 09-2023
Publisher: Elsevier BV
Date: 05-2015
Publisher: MDPI AG
Date: 10-11-2021
DOI: 10.3390/DIAGNOSTICS11112083
Abstract: The design and development of biosensors, analytical devices used to detect various analytes in different matrices, has emerged. Biosensors indicate a biorecognition element with a physicochemical analyzer or detector, i.e., a transducer. In the present scenario, various types of biosensors have been deployed in healthcare and clinical research, for instance, biosensors for blood glucose monitoring. Pathogenic microbes are contributing mediators of numerous infectious diseases that are becoming extremely serious worldwide. The recent outbreak of COVID-19 is one of the most recent ex les of such communal and deadly diseases. In efforts to work towards the efficacious treatment of pathogenic viral contagions, a fast and precise detection method is of the utmost importance in biomedical and healthcare sectors for early diagnostics and timely countermeasures. Among various available sensor systems, optical biosensors offer easy-to-use, fast, portable, handy, multiplexed, direct, real-time, and inexpensive diagnosis with the added advantages of specificity and sensitivity. Many progressive concepts and extremely multidisciplinary approaches, including microelectronics, microelectromechanical systems (MEMSs), nanotechnologies, molecular biology, and biotechnology with chemistry, are used to operate optical biosensors. A portable and handheld optical biosensing device would provide fast and reliable results for the identification and quantitation of pathogenic virus particles in each s le. In the modern day, the integration of intelligent nanomaterials in the developed devices provides much more sensitive and highly advanced sensors that may produce the results in no time and eventually help clinicians and doctors enormously. This review accentuates the existing challenges engaged in converting laboratory research to real-world device applications and optical diagnostics methods for virus infections. The review’s background and progress are expected to be insightful to the researchers in the sensor field and facilitate the design and fabrication of optical sensors for life-threatening viruses with broader applicability to any desired pathogens.
Location: India
Location: India
No related grants have been discovered for Atul Sharma.