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Jitendra Satija

Bio: Jitendra Satija is an academic researcher from VIT University. The author has contributed to research in topics: Dendrimer & Biosensor. The author has an hindex of 15, co-authored 33 publications receiving 673 citations. Previous affiliations of Jitendra Satija include Indian Institute of Technology Bombay.

Papers
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TL;DR: In this paper, the authors discuss various aspects of dendrimers from the point of view of sensor design, hoping that this review will excite more researchers into exploiting the exceptional properties of Dendrimer in biosensor development.
Abstract: The performance of biosensors, i.e. the sensitivity, specificity, linearity, reusability, chemical stability, and reproducibility is critically dependent on the biofunctionalization of the sensor platform. The type(s) of linkers used for the immobilization of the capture probes and the exact immobilization protocol play a vital role in the overall performance of sensors. A variety of linker molecules have been used to biofunctionalize technologically important substrates (glass, gold, mica etc.). Amongst the different linkers, researchers have paid more attention to two dimensional architectures, e.g.silanes, polyaniline (PANI), alkanethiols, poly-L-lysine (PLL), etc. Despite extensive research and a large number of reports, researchers still face problems related to limited loading efficiency, limited accessibility of the probes, poor control over uniform spacing among the probes and a loss of functionality due to irregular orientation of the probes, all of which cause variability in the responses. Three dimensional gel based matrices have proved to be a better choice, except for the fact that the leaching of entrapped probe molecules has limited their use in developing sensor platforms. Taking into account the limitations of the two dimensional linker arrays and three dimensional gel matrices, supramolecular dendritic architectures have shown immense potential in designing and developing the sensor platforms. Dendrimers are well-defined, monodispersed, globular macromolecules constructed around a core unit. Different properties of dendrimers, i.e. their structural uniformity, globular shape, monodispersity, the existence of dendritic crevices, high functional group density, hydrophilicity, versatility to design dendrimer of different composition and their nanometric size can be exploited while developing high sensitivity biosensors. Researchers have demonstrated that these hyperbranched 3D molecules show enhanced sensitivity, reduced nonspecific binding, greater accessibility of the probe for the target analyte, high stability and low variability in their response. Hence, designing a sensor with a dendrimer as a linker is a successful approach to obtain superior sensor performance and minimize the overall cost of a sensor. In this article, we discuss various aspects of dendrimers from the point of view of sensor design, hoping that this review will excite more researchers into exploiting the exceptional properties of dendrimers in biosensor development.

133 citations

Journal ArticleDOI
TL;DR: The paper highlights the different biocatalytic reactions and their role in plasmonic color development as a function of analyte concentration and concludes with an elucidation of current challenges and future perspectives of pELISA.
Abstract: The enzyme-linked immunosorbent assay (ELISA) has been an integral part of in vitro diagnostic tests due to its high specificity, standard configuration, and convenient readout. The convergence of the plasmonic property, i.e. localized surface plasmon resonance (LSPR), of noble metal nanoparticles with the ELISA technique has established a novel category of immunoassay, known as “plasmonic ELISA” (pELISA). It has enabled the naked eye detection of various disease biomarkers down to attomolar concentration. The color development relies on the biocatalytic reaction mediated modulation of LSPR properties. Through this review we present various current state-of-art pELISA strategies adopted for naked-eye quantification of disease biomarkers along with their advantages, limitations and applicability. These strategies are broadly classified into following four categories based on the different means of LSPR modulation: (i) aggregation, (ii) controlled growth kinetics, (iii) metallization, and (iv) etching of metal nanoparticles. Furthermore, the paper highlights the different biocatalytic reactions and their role in plasmonic color development as a function of analyte concentration. The review ends with an elucidation of current challenges and future perspectives of pELISA precisely focusing on the need for development of next generation low cost point-of-care diagnostic kits.

78 citations

Journal ArticleDOI
TL;DR: Dendrimers are hyperbranched, globular, monodisperse, nanometric polymeric architecture, having definite molecular weight, shape, and size, which make these an inimitable and optimum carrier molecule in pharmaceutical field and their utilization has been included in the scope of this review.
Abstract: Dendrimers are hyperbranched, globular, monodisperse, nanometric polymeric architecture, having definite molecular weight, shape, and size (which make these an inimitable and optimum carrier molecule in pharmaceutical field). Dendritic architecture is having immense potential over the other carrier systems, particularly in the field of drug delivery because of their unique properties, such as structural uniformity, high purity, efficient membrane transport, high drug pay load, targeting potential, and good colloidal, biological, and shelf stability. Despite their enormous applicability in different areas, the inherent cytotoxicity, reticuloendothelial system (RES) uptake, drug leakage, immunogenicity, and hemolytic toxicity restricted their use in clinical applications, which is primarily associated with cationic charge present on the periphery due to amine groups. To overcome this toxic nature of dendrimers, some new types of nontoxic, biocompatible, and biodegradable dendrimers have been developed (e.g., polyester dendrimer, citric acid dendrimer, arginine dendrimer, carbohydrate dendrimers, etc.). The surface engineering of parent dendrimers is graceful and convenient strategy, which not only shields the positive charge to make this carrier more biomimetic but also improves the physicochemical and biological behavior of parent dendrimers. Thus, surface modification chemistry of parent dendrimers holds promise in pharmaceutical applications (such as solubilization, improved drug encapsulation, enhanced gene transfection, sustained and controlled drug release, intracellular targeting) and in the diagnostic field. Development of multifunctional dendrimer holds greater promise toward the biomedical applications because a number of targeting ligands determine specificity in the same manner as another type of group would secure stability in biological milieu and prolonged circulation, whereas others facilitate their transport through cell membranes. Therefore, as a consequence of ideal hyperbranched architecture and the biocompatible nature of engineered dendrimers, their utilization has been included in the scope of this review, which focuses on current surface alteration strategies of dendrimers for their potential use in drug delivery and explains the possible beneficial applications of these engineered dendrimers in the biomedical field.

78 citations

Journal ArticleDOI
TL;DR: In this paper, a localized surface plasmon resonance (LSPR)-based fiber-optic probe was designed to obtain the highest possible refractive index (RI) sensitivity.
Abstract: The refractive index (RI) sensitivity of a localized surface plasmon resonance (LSPR)-based fiber-optic probes is dependent on surface coverage of gold nanoparticles (GNP), fiber core diameter, and probe geometry. For U-bent LSPR fiber-optic probes, which demonstrated an order higher absorption sensitivity over straight probes, bend diameter and probe length may also have a significant influence on the sensitivity. This study on U-bent fiber-optic LSPR probes is aimed at optimizing these parameters to obtain highest possible RI sensitivity. RI sensitivity increases linearly as a function of surface coverage of GNP in the range of 2–22 %. U-bent fiber-optic probes made of 200-, 400-, and 600-μm fiber core diameter show optimum bend diameter value as ∼1.4 mm. In addition, RI sensitivity is almost the same irrespective of fiber core diameter demonstrating flexibility in choice of the fiber and ease in optical coupling. The length of the probe preceding and succeeding the bend region has significantly less influence on RI sensitivity allowing miniaturization of these probes. In addition to these experimental studies, we present a theoretical analysis to understand the relative contribution of evanescent wave absorbance of GNP and refractive losses in the fiber due to GNP, towards the RI sensitivity.

77 citations

Journal ArticleDOI
01 Jun 2020
TL;DR: This work proposes to exploit the field-deployable/portable plasmonic fiber-optic absorbance biosensor (P-FAB) platform for one-step, wash-free detection of SARS-CoV-2 virus particles directly in saliva sample with minimal sample pre-processing.
Abstract: Rapid and low-cost diagnosis of COVID-19 is essential to identify the infected subjects, particularly the asymptomatic cases, primarily to arrest the spread of the disease through local transmission Antibody-based chromatographic serological tests, as an alternative to RT-PCR, offer only limited help due to high false positives We propose to exploit our field-deployable/portable plasmonic fiber-optic absorbance biosensor (P-FAB) platform for one-step, wash-free detection of SARS-CoV-2 virus particles directly in saliva sample with minimal sample pre-processing

75 citations


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Journal ArticleDOI
TL;DR: This critical review focuses on the design of biocompatible dendrimer-based nanoplatforms for targeted cancer diagnosis and therapy and theBiocompatibility aspects of d endrimers such as nanotoxicity, long-term circulation, and degradation are discussed.
Abstract: In the past decade, nanomedicine with its promise of improved therapy and diagnostics has revolutionized conventional health care and medical technology. Dendrimers and dendrimer-based therapeutics are outstanding candidates in this exciting field as more and more biological systems have benefited from these starburst molecules. Anticancer agents can be either encapsulated in or conjugated to dendrimer and be delivered to the tumour via enhanced permeability and retention (EPR) effect of the nanoparticle and/or with the help of a targeting moiety such as antibody, peptides, vitamins, and hormones. Imaging agents including MRI contrast agents, radionuclide probes, computed tomography contrast agents, and fluorescent dyes are combined with the multifunctional nanomedicine for targeted therapy with simultaneous cancer diagnosis. However, an important question reported with dendrimer-based therapeutics as well as other nanomedicines to date is the long-term viability and biocompatibility of the nanotherapeutics. This critical review focuses on the design of biocompatible dendrimers for cancer diagnosis and therapy. The biocompatibility aspects of dendrimers such as nanotoxicity, long-term circulation, and degradation are discussed. The construction of novel dendrimers with biocompatible components, and the surface modification of commercially available dendrimers by PEGylation, acetylation, glycosylation, and amino acid functionalization have been proposed as available strategies to solve the safety problem of dendrimer-based nanotherapeutics. Also, exciting opportunities and challenges on the development of dendrimer-based nanoplatforms for targeted cancer diagnosis and therapy are reviewed (404 references).

459 citations

Journal ArticleDOI
TL;DR: The present review briefly describes about dendrimer synthesis strategies, types of d endrimers with different functionalities, properties which having crucial importance and their potential applications.

455 citations

Journal ArticleDOI
TL;DR: Recent reports on delivery strategies, including conjugates of oligonucleotides with various ligands, as well as use of nanocarrier approaches, are reviewed in the context of intracellular trafficking pathways and issues regarding in vivo biodistribution of molecules and nanoparticles.
Abstract: The potential use of antisense and siRNA oligonucleotides as therapeutic agents has elicited a great deal of interest. However, a major issue for oligonucleotide-based therapeutics involves effective intracellular delivery of the active molecules. In this Survey and Summary, we review recent reports on delivery strategies, including conjugates of oligonucleotides with various ligands, as well as use of nanocarrier approaches. These are discussed in the context of intracellular trafficking pathways and issues regarding in vivo biodistribution of molecules and nanoparticles. Molecular-sized chemical conjugates and supramolecular nanocarriers each display advantages and disadvantages in terms of effective and nontoxic delivery. Thus, choice of an optimal delivery modality will likely depend on the therapeutic context.

424 citations

Journal ArticleDOI
05 Feb 2021-Sensors
TL;DR: A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal as mentioned in this paper, which can transform biological signals into electrochemical, electrical, optical, gravimetric, or acoustic signals.
Abstract: A biosensor is an integrated receptor-transducer device, which can convert a biological response into an electrical signal The design and development of biosensors have taken a center stage for researchers or scientists in the recent decade owing to the wide range of biosensor applications, such as health care and disease diagnosis, environmental monitoring, water and food quality monitoring, and drug delivery The main challenges involved in the biosensor progress are (i) the efficient capturing of biorecognition signals and the transformation of these signals into electrochemical, electrical, optical, gravimetric, or acoustic signals (transduction process), (ii) enhancing transducer performance ie, increasing sensitivity, shorter response time, reproducibility, and low detection limits even to detect individual molecules, and (iii) miniaturization of the biosensing devices using micro-and nano-fabrication technologies Those challenges can be met through the integration of sensing technology with nanomaterials, which range from zero- to three-dimensional, possessing a high surface-to-volume ratio, good conductivities, shock-bearing abilities, and color tunability Nanomaterials (NMs) employed in the fabrication and nanobiosensors include nanoparticles (NPs) (high stability and high carrier capacity), nanowires (NWs) and nanorods (NRs) (capable of high detection sensitivity), carbon nanotubes (CNTs) (large surface area, high electrical and thermal conductivity), and quantum dots (QDs) (color tunability) Furthermore, these nanomaterials can themselves act as transduction elements This review summarizes the evolution of biosensors, the types of biosensors based on their receptors, transducers, and modern approaches employed in biosensors using nanomaterials such as NPs (eg, noble metal NPs and metal oxide NPs), NWs, NRs, CNTs, QDs, and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology

401 citations

Journal ArticleDOI
TL;DR: This work presents a signal-generation mechanism that redefines the limit of detection of nanoparticle sensors by inducing a signal that is larger when the target molecule is less concentrated, and demonstrates the outstanding sensitivity and robustness of this approach.
Abstract: Nature Materials 11, 604-607 (2012); published online 27 May 2012; corrected after print 15 December 2017. In the version of this Letter originally published, the x and y values of the data points in Fig. 2c were incorrect. The original and corrected versions are shown below. The authors have also made some changes to the Supplementary Information: Fig.

384 citations