Bio: Sandeep Mishra is an academic researcher. The author has contributed to research in topics: Polyaniline. The author has an hindex of 1, co-authored 1 publications receiving 14 citations.
TL;DR: In this article, a flexible, disposable, and label free biosensing platform for detection of the cancer biomarker (carcinoembryonic antigen, CEA) is presented.
Abstract: We report results of studies relating to the fabrication of a flexible, disposable, and label free biosensing platform for detection of the cancer biomarker (carcinoembryonic antigen, CEA). Polyaniline (PANI) has been electrochemically deposited over gold sputtered paper (Au@paper) for covalent immobilization of monoclonal carcinoembryonic antibodies (anti-CEA). The bovine serum albumin (BSA) has been used for blocking nonspecific binding sites at the anti-CEA conjugated PANI/Au@Paper. The PANI/Au@Paper, anti-CEA/PANI/Au@Paper, and BSA/anti-CEA/PANI/Au@Paper platforms have been characterized using scanning electron microscopy, X-ray diffraction, Fourier transmission infrared spectroscopy, chronoamperometry, and electrochemical impedance techniques. The results of the electrochemical response studies indicate that this BSA/anti-CEA/PANI/Au@paper electrode has sensitivity of 13.9 μA ng−1 ml cm2, shelf life of 22 days, and can be used to estimate CEA in the range of 2–20 ng ml−1. This paper sensor has been v...
TL;DR: This review deals with four different types of carbon allotrope including carbon nanotubes, graphene, fullerenes and nanodiamonds and summarizes the results of recent studies that are likely to have implications in cancer theranostics.
Abstract: One of the major challenges in our contemporary society is to facilitate healthy life for all human beings. In this context, cancer has become one of the most deadly diseases around the world, and despite many advances in theranostics techniques the treatment of cancer still remains an important problem. With recent advances made in the field of nano-biotechnology, carbon-based nanostructured materials have drawn special attention because of their unique physicochemical properties, giving rise to great potential for the diagnosis and therapy of cancer. This review deals with four different types of carbon allotrope including carbon nanotubes, graphene, fullerenes and nanodiamonds and summarizes the results of recent studies that are likely to have implications in cancer theranostics. We discuss the applications of these carbon allotropes for cancer imaging and drug delivery, hyperthermia, photodynamic therapy and acoustic wave assisted theranostics. We focus on the results of different studies conducted on functionalized/conjugated carbon nanotubes, graphene, fullerenes and nanodiamond based nanostructured materials reported in the literature in the current decade. The emphasis has been placed on the synthesis strategies, structural design, properties and possible mechanisms that are perhaps responsible for their improved theranostic characteristics. Finally, we discuss the critical issues that may accelerate the development of carbon-based nanostructured materials for application in cancer theranostics.
TL;DR: The proposed immunoelectrode was validated with conventional ELISA for the detection of CEA in serum samples of cancer patients and resulted in improved electrochemical performance and signal stability.
Abstract: We report results of the studies relating to the fabrication of a label-free, flexible, light weight and disposable conducting paper based immunosensing platform comprising of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) and nanostructured iron oxide (nFe(2)O(3)@PEDOT:PSS) nanocomposite for detection of carcinoembryonic antigen (CEA), a cancer biomarker. The effect of various solvents such as sorbitol, ethanol, propanol, n-methyl-2-pyrrolidone (NMP) and dimethyl sulfoxide (DMSO) on the electrical conductivity of Whatman filter paper (WP) modified with nFe(2)O(3)@PEDOT:PSS/WP was investigated. The electrical conductivity of the PEDOT:PSS/WP electrode was found to be enhanced by two orders of magnitude (from 6.8 x 10(-4) to 1.92 x 10(-2) Scm(-1)) after its treatment with DMSO. Further, nFe(2)O(3) doped PEDOT:PSS/WP electrode exhibited the electrical conductivity as 2.4 x 10(-2) Scm(-1). Besides this, the incorporation of iron oxide nanoparticles (nFe(2)O(3)) into PEDOT:PSS/ WP resulted in improved electrochemical performance and signal stability. This nFe(2)O(3)@ PEDOT:PSS/WP based platform was used for immobilization of the anti-carcinoembronic antigen (anti-CEA) protein for quantitative estimation of cancer biomarker (CEA). The results of electrochemical response studies revealed that this conducting paper based immunoelectrode had a sensitivity of 10.2 mu Ang(-1) mLcm(-2) in the physiological range (4-25 ngmL(-1)) and shelf life of 34 days. Further, the proposed immunoelectrode was validated with conventional ELISA for the detection of CEA in serum samples of cancer patients. (C) 2019 Elsevier B.V. All rights reserved.
TL;DR: This review tracks the evolution of affinity sensors from conventional lateral-flow test strips to wearable/implantable devices enabled by soft and flexible materials and explores the possibilities for implantable/injectablesoft and flexible material-based affinity sensors.
Abstract: Recent advances in biosensors and point-of-care (PoC) devices are poised to change and expand the delivery of diagnostics from conventional lateral-flow assays and test strips that dominate the market currently, to newly emerging wearable and implantable devices that can provide continuous monitoring. Soft and flexible materials are playing a key role in propelling these trends towards real-time and remote health monitoring. Affinity biosensors have the capability to provide for diagnosis and monitoring of cancerous, cardiovascular, infectious and genetic diseases by the detection of biomarkers using affinity interactions. This review tracks the evolution of affinity sensors from conventional lateral-flow test strips to wearable/implantable devices enabled by soft and flexible materials. Initially, we highlight conventional affinity sensors exploiting membrane and paper materials which have been so successfully applied in point-of-care tests, such as lateral-flow immunoassay strips and emerging microfluidic paper-based devices. We then turn our attention to the multifarious polymer designs that provide both the base materials for sensor designs, such as PDMS, and more advanced functionalised materials that are capable of both recognition and transduction, such as conducting and molecularly imprinted polymers. The subsequent content discusses wearable soft and flexible material-based affinity sensors, classified as flexible and skin-mountable, textile materials-based and contact lens-based affinity sensors. In the final sections, we explore the possibilities for implantable/injectable soft and flexible material-based affinity sensors, including hydrogels, microencapsulated sensors and optical fibers. This area is truly a work in progress and we trust that this review will help pull together the many technological streams that are contributing to the field.
TL;DR: This is the first report on a flexible chemiresistive biosensor explored for the detection of the malaria biomarker and can be extended in the future to several other biomarker detection systems towards smart point-of-care (POC) diagnostics.
Abstract: We report the fabrication of a flexible, lightweight and disposable multi walled carbon nanotube (MWCNT)-zinc oxide (ZnO) nanofiber based chemiresistive biosensor for label free detection of the malaria biomarker, histidine rich protein II (HRP2). The sensing platform is formed by depositing nanofibers in between the source and drain electrodes patterned on a thin, flexible polyethylene terephthalate (PET) substrate. MWCNT-ZnO nanofibers are synthesized via the electrospinning technique followed by a calcination process. This approach creates functional groups on the nanofiber surface that are used for the one step immobilization of HRP2 antibodies without further surface modification. The device exhibits a good sensitivity of 8.29 kΩ g-1 mL and a wide detection range of 10 fg mL-1-10 ng mL-1, and it is specific towards the targeted HRP2 biomarker. To the best of our knowledge, this is the first report on a flexible chemiresistive biosensor explored for the detection of the malaria biomarker and can be extended in the future to several other biomarker detection systems towards smart point-of-care (POC) diagnostics.
09 Sep 2019
TL;DR: A review of the basic characteristics of paper and its functionalization with nanomaterials, methodology for device fabrication, and their various applications highlights some of the exciting applications of CP in point‐of‐care diagnostics for biomedical applications.
Abstract: The emerging demand for wearable, lightweight portable devices has led to the development of new materials for flexible electronics using non-rigid substrates. In this context, nanomaterial-modified conducting paper (CP) represents a new concept that utilizes paper as a functional part in various devices. Paper has drawn significant interest among the research community because it is ubiquitous, cheap, and environmentally friendly. This review provides information on the basic characteristics of paper and its functionalization with nanomaterials, methodology for device fabrication, and their various applications. It also highlights some of the exciting applications of CP in point-of-care diagnostics for biomedical applications. Furthermore, recent challenges and opportunities in paper-based devices are summarized.