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    Anti-aggregation of gold nanoparticles for metal ion discrimination: a promising strategy to design colorimetric sensor arrays

    , Article Sensors and Actuators, B: Chemical ; Volume 270 , 2018 , Pages 545-551 ; 09254005 (ISSN) Najafzadeh, F ; Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Abstract
    The first report of anti-aggregation-based sensor arrays is presented. The strategy is based on the competitive interaction of citrate-capped gold nanoparticles (AuNPs) and heavy metal ions (i.e., Hg(II), Ag(I), Fe(III), and Pb(II)) with three aggregation reagents (i.e., cysteine, melamine, and arginine). In the presence of aggregation reagent, the color and UV–vis spectra of AuNPs are changed indicating the aggregation of AuNPs. Addition of the aggregation reagents which are firstly treated with the ions, causes AuNPs turn from the aggregation to the dispersion state. The anti-aggregation capability of ions towards various aggregation reagents is different because of distinct stability... 

    Analytical figures of merit for multisensor arrays

    , Article ACS Sensors ; Volume 5, Issue 2 , 2020 , Pages 580-587 Parastar, H ; Kirsanov, D ; Sharif University of Technology
    American Chemical Society  2020
    Abstract
    Multisensor arrays employing various sensing principles are a rapidly developing field of research as they allow simple and inexpensive quantification of various parameters in complex samples. Quantitative analysis with such systems is based on multivariate regression techniques, and deriving of traditional analytical figures of merit (e.g., sensitivity, selectivity, limit of detection, and limit of quantitation) for such systems is not obvious and straightforward. Nevertheless, it is absolutely needed for further development of the multisensor research field and for introducing these instruments into the general context of analytical chemistry. Here, we report on the protocol for... 

    ThThnated Development of a pH assisted AgNP-based colorimetric sensor Array for simultaneous identification of phosalone and azinphosmethyl pesticides

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 219 , 2019 , Pages 496-503 ; 13861425 (ISSN) Orouji, A ; Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Development of simple and rapid methods for identification of pesticides, due to their broad usage and harmful effects on mammals, has been known as a critical demand. Herein, we have introduced a silver nanoparticle (AgNP)based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM)and Phosalone (PS)pesticides. In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5)showed different aggregation behaviors. As a result of aggregation, the color and UV–Vis spectra of AgNPs changed differentially, leading to distinct response patterns for AM and PS. The aggregation induced spectral changes of AgNPs, were used to identify AM and PS... 

    Identification of catecholamine neurotransmitters using fluorescence sensor array

    , Article Analytica Chimica Acta ; Volume 917 , 2016 , Pages 85-92 ; 00032670 (ISSN) Ghasemi, F ; Hormozi Nezhad, M. R ; Mahmoudi, M ; Sharif University of Technology
    Elsevier B.V  2016
    Abstract
    A nano-based sensor array has been developed for identification and discrimination of catecholamine neurotransmitters based on optical properties of their oxidation products under alkaline conditions. To produce distinct fluorescence response patterns for individual catecholamine, quenching of thioglycolic acid functionalized cadmium telluride (CdTe) quantum dots, by oxidation products, were employed along with the variation of fluorescence spectra of oxidation products. The spectral changes were analyzed with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify catecholamine patterns. The proposed sensor could efficiently discriminate the individual... 

    Design of Chemiluminescence Sensors Enhanced by Colloidal Nanoparticles for Discrimination of Biomolecules

    , Ph.D. Dissertation Sharif University of Technology Shahrajabian, Maryam (Author) ; Hormozinezhad, Mohammad Reza (Supervisor)
    Abstract
    In the first part of this research, we introduce a novel chemiluminescence (CL) sensor array for discrimination of biothiols (e.g., cysteine, glutathione and glutathione disulfide). The proposed CL sensor array is based on the CL efficiencies of four types of enhanced nanoparticle-based CL systems. The intensity of CL was altered to varying degrees upon interaction with biothiols, producing unique CL response patterns. These distinct CL response patterns were collected as “fingerprints” and were then identified through chemometric methods, including linear discriminant analysis (LDA) and hierarchical cluster analysis (HCA). The developed array was able to successfully differentiate between... 

    Design of a Colorimetric Sensor Array Based on Aggregation of Gold Nanoparticles for Identification and Discrimination of Pesticides

    , M.Sc. Thesis Sharif University of Technology Mirghafouri, Mohammad Reza (Author) ; Hormozinezhad, Mohammad Reza (Supervisor) ; Ghasemi, Forough (Supervisor)
    Abstract
    There is great attention in developing rapid and straightforward methods for the identification of various pesticides that are usually used simultaneously in agricultural products. It is due to the extensive use of a diverse class of pesticides in agricultural products and their high toxicity which causes serious diseases in the human body. In the current study, a non-enzymatic sensor array has been developed for the identification and discrimination of five different pesticides belong to diverse classes including organophosphate, carbamate, and bipyridylium. For this aim, gold nanoparticles with two different capping agents consisting of citrate and borohydride were used as sensing... 

    Design of a Colorimetric Sensor Array Based on Aggregation of Gold Nanoparticles on the Surface of Probiotic Bacteria for Identification and Discrimination of Antiseptic Alcohols

    , M.Sc. Thesis Sharif University of Technology Ghamsari, Mahdi (Author) ; Hormozinezhad, Mohammad Reza (Supervisor)
    Abstract
    The occurrence of the COVID-19 pandemic and the subsequent rising demand for purchasing alcohol-based sanitizers led to a remarkable prosperity in supplying these hygiene products. Hence, the development of a straightforward and efficient analytical strategy for discrimination of antiseptic alcohols including methanol, ethanol and isopropanol is of great importance. By exploiting the alcohol-sensitive membranes of probiotic bacteria, this research aims to develop a colorimetric sensor array for discriminating methanol, ethanol and isopropanol. In this design, the aggregation of citrate-capped gold nanoparticles (Au NPs) on the thiol-modified surface of two probiotic bacteria, including... 

    Determination of nanoparticles using UV-Vis spectra

    , Article Nanoscale ; Volume 7, Issue 12 , Feb , 2015 , Pages 5134-5139 ; 20403364 (ISSN) Behzadi, S ; Ghasemi, F ; Ghalkhani, M ; Ashkarran, A. A ; Akbari, S. M ; Pakpour, S ; Hormozi Nezhad, M. R ; Jamshidi, Z ; Mirsadeghi, S ; Dinarvand, R ; Atyabi, F ; Mahmoudi, M ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Abstract
    Nanoparticles (NPs) are increasingly being used in different branches of science and in industrial applications; however, their rapid detection and characterization at low concentration levels have remained a challenge; more specifically, there is no single technique that can characterize the physicochemical properties of NPs (e.g. composition and size). In this work we have developed a colorimetric sensor array for defining the physicochemical properties of NPs in aqueous solution with ultra-low concentrations (e.g. 10-7g ml-1 for gold NPs). Various NPs were readily identified using a standard chemometric approach (i.e. hierarchical clustering analysis), with no misclassifications over 400... 

    Traffic aware dynamic node scheduling for power efficient sensor networks

    , Article 2004 Intelligent Sensors, Sensor Networks and Information Processing Conference, ISSNIP '04, Melbourne, 14 December 2004 through 17 December 2004 ; 2004 , Pages 37-42 ; 0780388933 (ISBN); 9780780388932 (ISBN) Ghannad Rezaie, M ; Shah Mansouri, V ; Pakravan, M. R ; Sharif University of Technology
    2004
    Abstract
    This paper proposes a new medium-access control (MAC) protocol designed for wireless sensor networks. A wireless sensor network is an array of large number of sensors interconnected by a multi-hop ad-hoc network. The primary objective for the sensor network is achieving to low-power consumption while latency is usually less important compare to traditional wireless networks. This characteristic of sensor network motivates the design of new MAC layer so that power consumption is reduced. In this paper, a novel traffic-aware algorithm based on distributed node schedule management (DMD) protocol is introduced that utilizes distributed dynamic node scheduling strategy to dramatically increase... 

    A novel approach to radio direction finding and detecting the number of sources simultaneously: DMSAE algorithm

    , Article Conference Proceedings- 34th European Microwave Conference, London, 12 October 2004 through 14 October 2004 ; Volume 2 , 2004 , Pages 745-748 ; 1580539920 (ISBN) Movahhedi, M ; Tadaion, A. A ; Aref, M. R ; Sharif University of Technology
    2004
    Abstract
    In smart antenna systems, The localization and direction of desired source(s) must be known. In this paper, we introduce a method called "DMSAE" (Direction finding of Multiple Sources by Alternating Eliminations) to find the radio directions of signals impinging on an arbitrary antenna array and the number of the signals. This method which is based on the Minimum Variance Distortionless Response (MVDR) algorithm, can not only detect the direction and the number of sources, simultaneously, but also has better resolution ability compared to the other conventional direction finding algorithms. This method can also detect very weak sources when other powerful sources exist in the environment. In... 

    Determination of reflectance optical sensor array configuration using 3-layer tissue model and Monte Carlo simulation

    , Article IFMBE Proceedings, 20 June 2011 through 23 June 2011 ; Volume 35 IFMBE , 2011 , Pages 424-427 ; 16800737 (ISSN) ; 9783642217289 (ISBN) Jumadi, N. A ; Gan, K. B ; Mohd Ali, M. A ; Zahedi, E ; Sharif University of Technology
    2011
    Abstract
    A new reflectance optical sensor array for locating fetal signal transabdominally has been determined in this study. The selection of optical sensor array is based on the highest Irradiance (μW/m2) value estimated on respected detectors. A three-layer semi-infinite tissue model which consists of maternal, amniotic fluid sac and fetal tissues is employed to study the optical sensor array configuration. By using statistical error approach, the number of rays injected to the system can be set to 1 million rays with ±3.2% of simulation error. The simulation results obtained from Monte Carlo technique reveal that diamond configuration is the most suitable configuration of reflectance optical... 

    Identification of catecholamine neurotransmitters using fluorescence sensor array

    , Article Analytica Chimica Acta ; Volume 917 , April , 2016 , Pages 85–92 ; 00032670 (ISSN) Ghasemi, F ; Hormozi Nezhad, M. R ; Mahmoudi, M ; Sharif University of Technology
    Elsevier  2016
    Abstract
    A nano-based sensor array has been developed for identification and discrimination of catecholamine neurotransmitters based on optical properties of their oxidation products under alkaline conditions. To produce distinct fluorescence response patterns for individual catecholamine, quenching of thioglycolic acid functionalized cadmium telluride (CdTe) quantum dots, by oxidation products, were employed along with the variation of fluorescence spectra of oxidation products. The spectral changes were analyzed with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify catecholamine patterns. The proposed sensor could efficiently discriminate the individual... 

    A multichannel single-well sensor array for rapid and visual discrimination of catecholamine neurotransmitters

    , Article Sensors and Actuators, B: Chemical ; Volume 296 , 2019 ; 09254005 (ISSN) Abbasi Moayed, S ; Hormozi Nezhad, M. R ; Maaza, M ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    In this study, for rapid identification and discrimination of catecholamine neurotransmitters in the presence of ascorbic acid (AA), a tricolor fluorescence probe has been constructed by integrating three recognition elements including blue carbon dots (bCDs), green CdTe quantum dots (gQDs) and red CdTe quantum dots (rQDs) into a single well. The proposed array exhibited ternary fluorescence emissions at 450, 520 and 630 nm with an overall luminescent pink emission under a single wavelength excitation (365 nm). In order to produce distinct response patterns from a single fluorimetric test, the spectral changes and the corresponding color variations of the multichannel fluorescence probe were... 

    Determination and identification of nitroaromatic explosives by a double-emitter sensor array

    , Article Talanta ; Volume 201 , 2019 , Pages 230-236 ; 00399140 (ISSN) Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Detection of nitroaromatic explosives is of strong concern because of human health, public safety, environment, and military issues. In this study, we present a ratiometric sensor array for detection and discrimination of widely-used nitroaromatics (i.e., 2,4,6-trinitrotoluene (TNT), 2,4,6-trinitrophenol (TNP), and 2,4-dinitrotoluene (DNT)). In the design of sensor elements (SE) we employ blue emissive carbon dots (BCDs) in combination with yellow (SE-A) and red (SE-B) emissive cadmium telluride quantum dots (CdTe QDs). The fluorescence intensity of BCDs, YQDs, and RQDs is quenched by TNT, DNT, and TNP in various degrees. Both TNT and TNP cause the quenching and spectral shift of BCDs (TNT... 

    Chemiluminometric fingerprints for identification of plasmonic nanoparticles

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 209 , 2019 , Pages 85-94 ; 13861425 (ISSN) Shahrajabian, M ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Development of a convenient and inexpensive method for identification and detection of nanoparticles (NPs) is of great interest. In this work, we have developed a novel and simple chemiluminescence based sensor array, with its sensing mechanism mimicking that of olfactory and gustatory systems for discriminating a set of NPs. The proposed method is based on the enhancement effect of NPs on luminol–oxidant CL intensity by their catalytic effect. Three kinds of oxidant including H2O2, AgNO3, and K3Fe(CN)6 were used as sensor elements and NPs exhibited diverse enhancing responses to different oxidant-luminol CL systems producing unique response patterns that were identified through heat map and... 

    Colorimetric Sensor Array Design for Classification and Detection of Nanoparticles and Some Biomolecules

    , Ph.D. Dissertation Sharif University of Technology Ghasemi, Forough (Author) ; Hormozi Nezhad, Mohammad Reza (Supervisor)
    Abstract
    In the first part of this research, we reported a liquid sensor array for detection and classification of biological thiols, based on aggregation of gold nanoparticles (AuNPs) with different coatings as sensor elements. Thiol mediated aggregation of AuNPs was visualized via UV–vis spectra. The spectral changes, as a consequence of aggregation of AuNPs, made a unique pattern of spectra for each analyte and allowed for the selective detection and discrimination of the biological molecules. HCA and PCA analysis demonstrated the discrimination of various thiols of different concentrations (i.e. 10–800 mmol L-1 for cysteine, 200–700 mmol L-1 for both glutathione and glutathione disulfide).... 

    Design of an Optoelectronic Tongue Based on Anti-Aggregation of Gold Nanoparticles for Detection and Classification of Heavy Metal Ions

    , M.Sc. Thesis Sharif University of Technology Najafzadeh, Fatemeh (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
    Abstract
    The first report of anti-aggregation-based sensor arrays is presented. The strategy is based on the competitive interaction of citrate-capped gold nanoparticles (AuNPs) and heavy metal ions (i.e., Hg(II), Ag(I), Fe(III), and Pb (II)) with three aggregation reagents (i.e., cysteine, melamine, and arginine). In the presence of aggregation reagent,the color and UV–vis spectra of AuNPs are changed indicating the aggregation ofAuNPs. Addition of the aggregation reagents which are firstly treated with the ions, causes AuNPs turn from the aggregation to the dispersion state. The anti-aggregation capability of ions towards various aggregation reagents is different because of distinct stability... 

    Synthesis of Luminescent Carbon Dots for Selectivity Study Towards Metal Ions

    , M.Sc. Thesis Sharif University of Technology Ghasemi, Nazer Hossein (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor)
    Abstract
    Today, the use of graphene quantum dots has been very much considered due to easy synthesis methods, strong fluorescence emission, and many sources of synthesis. In this study, the effect of changing capping agent of graphene quantum dots toward iron (Ⅲ), copper (Ⅱ) and mercury (Ⅱ) ions was studied. The linear range of response of the graphene quantum dots synthesized with ethylenediamine for mercury (Ⅱ) and iron (Ⅲ) ions was 10-70 µM, and this sensor also responded to Cu (Ⅱ) ions. Urea synthesized graphene quantum dots also responded to all three ions. The linear range of the response for mercury (Ⅱ) , iron (Ⅲ) and copper (Ⅱ) ions was 5-25, 10-70 and 120-120 μM respectively. The linear... 

    Developments of Fluorescence Sensor Arrays Using Nanostructured Sensor Elments and Nanocellulose Substrate for Identification and Discrimination of Biomolecules and Environmental pollutants

    , Ph.D. Dissertation Sharif University of Technology Abbasi-Moayed, Samira (Author) ; Hormozi-Nezhad, Mohammad Reza (Supervisor) ; Golmohammadi Ghaneh, Hamed (Co-Supervisor)
    Abstract
    In the first part of this research, a ratiometric fluorescent sensor array has been developed on nanocellulose platform towards chemical discrimination applications. Bacterial nanocellulose (BC) was utilized for the first time as a novel, flexible and transparent substrate in optical sensor arrays for developing portable and high performance sensor array.. To fabricate this platform, the hydrophobic walls on BC nanopaper substrates were successfully created using laser printing technology. In addition, we have used the properties of immobilized ratiometric fluorescence sensor elements (Carbon Dots- Rhodamine B (CDs-RhB) nanohybrids) on nanopaper platform to improve the visual... 

    Design of Colorimetric Sensor Array for Simultanous Detection of Phosalone and Azinphosmethyl Pesticides Based on Aggregation Silver Nanoparticles (AgNPs)

    , M.Sc. Thesis Sharif University of Technology Orouji, Afsaneh (Author) ; Hormozinezhad, Mohammad Reza (Supervisor)
    Abstract
    Development of simple and rapid approaches for identification of pesticides has been known as a critical demand, due to the broad usage of pesticides and their harmful effects on mammals. Herein, we have introduced a silver nanoparticle (AgNP) based colorimetric sensor array for simultaneous identification of Azinphosmethyl (AM) and Phosalone (PS). In the presence of the target pesticides, unmodified AgNPs at various pHs (4.5, 5.5 and 9.5) showed different aggregation behaviours. As a result of aggregation, the color and UV-Vis spectra of AgNPs changed which led to distinct patterns for AM and PS. The aggregation induced spectral changes of AgNPs were used to identify AM and PS with the help...