Browsing by Author "Camarada, Maria Belen"

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    A first-principles study on the adsorption properties of phosphorene oxide for pollutant removal from water
    (2022) Cortes-Arriagada, Diego; Barria, Natacha; Ortega, Daniela E.; Araya-Duran, Ingrid; Camarada, Maria Belen
    Phosphorene-based materials have emerged as useful platforms for new technological applications, including their potential implementation in the solid-phase extraction of pollutants. In this study, we implemented a first-principles study to characterize the interactions between water-soluble pollutants and phosphorene oxide (PhosO) at the microscopic level, providing useful mechanistic insights into the role of phosphorene oxidation in its adsorption/removal ability. Continuum/explicit solvent effects were considered to explain the solvent role, and the ALMO-EDA method characterizes the intermolecular forces. Our results show that PhosO significantly adsorbs pollutants on its surface by inner surface adsorption, even under aqueous environments, and provides remarkable adsorption stability for a wide family of water-soluble emerging contaminants (pharmaceuticals, endocrine disruptors, flame retardants, and industrial chemicals) with adsorption energies of 0.53 to 1.17 eV. The stabilizing energy in solution is driven by a balanced contribution of dispersion and electrostatic driving forces (up to 83% of the stabilizing energy), overcompensating all the destabilizing effects from the solvation process and Pauli repulsion. Furthermore, PhosO promotes low pollutant mobility from its surface under water molecules, which are not competitive factors in the adsorption process. In addition, simulations under dynamic conditions show that the electrostatic/dispersion governed mechanism remains stable at room conditions for real-life applications (300 K, 1 atm). Finally, a bandgap increase of 0.73 eV is noted in PhosO upon pollutant adsorption, giving a suitable framework for further sensing applications of contaminants by increasing the metallic character of PhosO. These results expand the understanding of the role of phosphorene oxidation for its use as a removal platform in water treatment technologies. (c) 2022 Elsevier B.V. All rights reserved.
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    A portable smart detection and electrocatalytic mechanism of mycophenolic acid: A machine learning-based electrochemical nanosensor to adapt variable-pH silage microenvironment
    (2022) Ge, Yu; Camarada, Maria Belen; Liu, Peng; Qu, Mingren; Wen, Yangping; Xu, Lanjiao; Liang, Huan; Liu, En; Zhang, Xian; Hao, Wenxue; Wang, Long
    The pH of silage microenvironment is protean which affects the concentration of mycophenolic acid (MPA) that is an animal health-threatening mycotoxin produced by Penicillium roqueforti. This inspired us to develop a fast portable intelligent method for electrochemical detection of MPA in silage with the variable-pH microenviron-ment using Zn-Co MOF/Ti3C2 MXene/Fe3O4-MGO coupling with machine learning (ML). Zn-Co MOF (metal organic framework), Ti3C2 MXene (graphene-like titanium carbide MXene), Fe3O4-MGO (magnetic Fe3O4-gra-phene oxide) and their nanocompsite with excellent electrocatalytic capacity were prepared and characterized. The electrocatalytic mechanism of MPA was investigated by density functional theory (DFT) and electrochemical experiments, which clarified the most easily redox position of MPA. ML model via artificial neural network (ANN) algorithm for smart output of MPA through input of pH was discussed that adapt to the variable-pH microenvironment and realize intelligent analysis of MPA in silage with the variable-pH microenvironment. R2 near 1, lower both RMSE and MAE, and higher RPD value demonstrate the good predictive performance and high predictive accuracy of the proposed ANN model. This will provide a fast portable wireless intelligent sensing analytical technology for detecting hazardous substances in diverse complicated and changeable outdoor microenvironments
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    A stable nanosilver decorated phosphorene nanozyme with phosphorus- doped porous carbon microsphere for intelligent sensing of 8-hydroxy-20-deoxyguanosine
    (2021) Sheng, Yingying; Zhu, Yifu; Ceron, Maria Luisa; Yi, Yufu; Liu, Peng; Wang, Peng; Xue, Ting; Camarada, Maria Belen; Wen, Yangping
    Nanozyme based on the silver nanoparticles (AgNPs) decorated highly water-oxygen stable phosphorene (BP) nanohybrid with phosphorus-doped porous carbon microspheres (P-PCMs) is applied as an intelligent sensing platform for the electrochemical detection of 8-hydroxy-20-deoxyguanosine (8-OHdG) as a biomarker of oxidative DNA damage in human urine sample. The density functional theory (DFT) is use for investigating the effect of silver on the conductivity level of BP and discussing a possible mechanism for the electrocatalytic oxidation of 8-OHdG. The Ag+ is in-situ reduced as AgNPs that grows onto the BP surface for the controllable preparation of BP-AgNPs with effective surface passivation among different metal ions decorated BP. P-PCMs with 4.9-fold enhancement in specific surface area (1636.73 m2 g-1) are prepared by hydrothermal carbonization of alpha cyclodextrin as carbon sources, then calcinate in the presence of phosphoric acid as an activator and dopant. P-PCMs-BP-AgNPs are prepared by the ultrasound-assisted liquid-phase exfoliation with the addition of Ag+, and both P-PCMs and black phosphorus crystals are sufficiently grinded. The P-PCMs-BP-AgNPs nanohybrid displays good long-term water-oxygen stability, extraordinary specific surface area, superior electrocatalytic capacity with 303-fold enhancement, enzyme-like characteristics with Imax of 100 mu A and Km of 29 mu M. The machine learning (ML) model with artificial neural network (ANN) algorithm is employed for the intelligent output of 8-OHdG in real sample with acceptable recovery in work range from 0.2 to 125 mu M.
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    An antifouling electrochemical sensor based on multiwalled carbon nanotubes functionalized black phosphorus for highly sensitive detection of carbendazim and corresponding response mechanisms analyses
    (2023) Liao, Xiaoning; Luo, Xiaoyao; Li, Yiyang; Zhou, Ying; Liang, Qi; Feng, Kehuai; Camarada, Maria Belen; Xiong, Jianhua
    Carbendazim (CBZ) was widest used in agriculture for its high efficiency in controlling of fungal diseases. However, CBZ can pose serious contamination to agricultural products and water resource for its long half-lives and high toxicity. Therefore, precise detection of CBZ residues is very important for human health and envi-ronmental safety concerns. Nevertheless, the inherent electrode fouling effect caused by CBZ products hinders the precise and practical determination of CBZ. Herein, a novel highly antifouling heterostructure based on carboxylated multiwalled carbon nanotubes (MWCNT-COOH) functionalized black phosphorus (BP) have been successfully developed via a facile sonication assisted self-assembly method. The electrochemical interface of BP/ MWCNT-COOH modified glassy carbon electrode shows excellent catalytic activity to CBZ oxidation and good electrode antifouling effect, ensuring repeatable and precise detection of CBZ. In addition, the sensor shows a wide linearity from 9.0 nM to 1000 nM with a detection limit of 4.0 nM which superior to most of previous work. Moreover, the BP-based non-enzymatic sensor shows good selectivity and satisfactory recoveries for real sample analysis, confirming its highly practical application. The antifouling mechanism to CBZ for the sensor and the interaction mechanism between MWCNTs-COOH and BP were also illustrated by theory calculations.
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    Evaluation of electro-synthesized oligothiophenes as donor materials in vacuum-processed organic photovoltaic devices
    (2023) Camarada, Maria Belen; Saldias, Cesar; Castro-Castillo, Carmen; Angel, Felipe A.
    2,2 ':5 ',2 ''-terthiophene (3Th) was utilized as a precursor in the electro-synthesis of oligothiophenes and their further evaluation as donor materials in the active layer of vacuum-processed organic photovoltaic (OPV) devices. Electro-polymerization conditions were optimized to obtain a controlled fraction of polydisperse oligomers, as demonstrated by size exclusion chromatography (SEC). The polydispersity of the material was further decreased during thermal evaporation, where a reduced fraction of the oligomer was deposited, as observed by SEC, absorption spectroscopy, and the characterization of the fabricated devices. Our results demonstrate for the first time the potential of the electro-synthesis of oligothiophenes as active materials for their application in bulk heterojunction for OPV devices.
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    Green and accurate analytical method for monitoring atropine in foodstuffs as a contaminant and in pharmaceutical samples
    (2023) Hamidian, Yasamin; Mostafazadeh, Reza; Erk, Nevin; Karaman, Ceren; Camarada, Maria Belen; Dragoi, Elena-Niculina
    Nowadays, atropine has been highlighted because of its anticholinergic effect and contamination in foodstuffs, and therefore, using an accurate and sensitive method for its determination is crucial in human health and food safety. In this study, a novel spectrophotometric method was suggested for the swift quantification of atropine. The proposed method was based on the formation of red ion-pair complexes between the drugs and the cyanidin reagent extracted from red cabbage ( RC). In this regard, the effect of pH, time, and temperature was explored and optimized. According to the results, atropine determining was shown the best performance in pH 2 at room temperature in 30 min. In addition, this method revealed linear responses from 10 nM to 1 mu M of atropine with limit of detection (LOD) value of 0.0019 mu M. Also, the selectivity value of this method was investigated in the presence of some drugs with the same structure and some common species as interferences. The results verified no interference in atropine determination, as well as, the results obtained from repeatability (RSD. 2.56) of this method were acceptable. Moreover, the applicability of this method was tested in buckwheat and atropine sulfate as food and pharmaceutical real sample, respectively. Real sample analysis was carried out with the standard addition method and the recovery percentages (96.54-104.87%) witnessed the high capability of this method in atropine determination.
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    MoS2 quantum dots and titanium carbide co-modified carbon nanotube heterostructure as electrode for highly sensitive detection of zearalenone
    (2022) Huang, Hao; Camarada, Maria Belen; Wang, Dan; Liao, Xiaoning; Xiong, Wanming; Du, Juan; Xiong, Jianhua; Hong, Yanping
    A novel electrochemical sensor has been fabricated for sensitive determination of zearalenone (ZEA) in food samples based on molybdenum disulfide quantum dots (MoS2 QDs) and two-dimensional titanium carbide (2D-Ti3C2Tx MXene) co-modified multi-walled carbon nanotube (MWCNT) heterostructure. Physical and electrochemical characterizations reveal that 2D-Ti3C2Tx and MoS2 QDs co-modified MWCNTs yields synergistic signal amplification effect, together with large specific surface area and excellent conductivity for the heterostructure, endowing the developed sensor with high detection performance to ZEA. Under optimized conditions, the sensor shows a wide linear range from 3.00 to 300 ng mL(-1) and a low limit of detection (LOD) of 0.32 ng mL(,)(-1) which is far lower than the maximum residue limits (MRLs) settled by the European Commission. In addition, it exhibits excellent selectivity, high reproducibility with a relative standard deviation (RSD) of 1.1%, and good repeatability (RSD 1.1%). In real sample analysis recoveries ranged from 94.8 to 105% showing the proposed electrochemical sensor has high potential in practical applications. This work presents an effective and valuable pathway for the use of novel heterostructure in the biosensing field.
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    One-step electrochemical preparation of platinum nanoparticle decorated self-healing reduced graphene oxide three-dimensional nanoarray for portable detection of bisphenol A
    (2024) Jayakumar, Kumarasamy; Zhong, Ying; Camarada, Maria Belen; Lu, Xinyu; Chen, Tao; Zhang, Weimin; Wen, Yangping
    Highly selective and sensitive analysis of bisphenol A (BPA) in many plastic products remains its significance. We explored a simple, highly sensitive, and inexpensive electrochemical sensor based on a self-healing threedimensional nanoarray (3DN) via a single-step electrochemical preparation of both platinum nanoparticles (PtNPs) and reduced graphene oxide (rGO) on a glassy carbon electrode for the portable detection of bisphenol (BPA) in plastic bottled waters. The structure of PtNPs/3DNrGO was confirmed by electron microscope and spectroscopic characterization. Electrochemical characteristics indicated that PtNPs/3DNrGO could decrease the oxidation overpotential due to the self-healing effect of the physical interaction between PtNPs and hydroxyl groups of rGO with an increase in the active surface area. The PtNPs/3DNrGO exhibited remarkably efficient electrocatalytic performance for the oxidation of BPA. The PtNPs/3DNrGO sensor for BPA demonstrated a wide linear range from 0.7 to 20 mu M with a low limit of detection of 6 nM (S/N = 3) and effective performance including high sensitivity, high repeatability, and excellent selectivity. The developed sensor had been effectively implemented to assess BPA in plastic samples with desirable impacts. The interaction mechanism of both PtNPs and rGO was inferred by density functional theory. The proposed electrochemical sensor enabled the development of a portable, low-cost, and user-friendly monitoring of water quality, which will offer theoretical support for environmental monitoring.
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    Synthesis of NiO-Doped ZnO Nanoparticle-Decorated Reduced Graphene Oxide Nanohybrid for Highly Sensitive and Selective Electrochemical Sensing of Bisphenol A in Aqueous Samples
    (2023) Buledi, Jamil A.; Shaikh, Huma; Solangi, Amber R.; Mallah, Arfana; Shah, Zia-ul-Hassan; Khan, Mir Mehran; Sanati, Afsaneh L.; Karimi-Maleh, Hassan; Karaman, Ceren; Camarada, Maria Belen; Niculina, Dragoi Elena
    Bisphenol A (BPA) is broadly used in the plastic industry and has several health effects, especially on the brain and prostate gland of fetuses. BPA is a major environmental pollutant that drains into bodies of water and leaches from food packaging. Since it is a known endocrine disruptor, its extensive release into the environment is a serious concern. Thus, regular monitoring of BPA through a reliable and sensitive method is a strategy that can help alleviate its impact. To tackle this issue, an excellent conductive material based on a NiO/ZnO/rGO nanohybrid was used as an electrocatalyst to determine BPA in drinking water samples. The engineered material was characterized through XRD, EDX, and SEM. The EDX mapping was also used to examine the purity, surface texture, and focused elemental composition of the NiO/ZnO/rGO nanohybrid. The average size of the prepared material was calculated as 43.7 nm, which confirmed the nanometric size of the engineered nanohybrid material. The conductive behavior of the fabricated sensor NiO/ZnO/rGO/PtE was examined through electrochemical impedance spectroscopy (EIS) and cyclic voltammetry. The modified sensor revealed an excellent conductive nature with ohmic resistance calculated to be 412 omega, which is lower than that of the bare electrode and GO/PtE (3628 and 2239 omega, respectively). Under optimal parameters, the fabricated sensor showed excellent response for BPA. With a linear dynamic range of 0.07-30 mu M, NiO/ZnO/rGO/PtE manifested the lowest possible detection limit found (4.0 nM). The analytical applicability of the proposed sensor was investigated in bottled and tap water. Furthermore, both the acceptable recovery values and anti-interference ability indicated the effectiveness and potential commercial utilization of NiO/ZnO/rGO/PtE. The recovery values for mineral and tap water were 97.0%, 99.0%, and 97.3% and 101%, 99.6%, and 98.7%, respectively.
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    The interaction mechanism of polystyrene microplastics with pharmaceuticals and personal care products
    (2023) Cortes-Arriagada, Diego; Miranda-Rojas, Sebastian; Camarada, Maria Belen; Ortega, Daniela E.; Alarcon-Palacio, Victoria B.
    Microplastics (MPs) have been detected in the hydrosphere, with hazardous implications in transporting coexisting water pollutants. Our knowledge about the interaction mechanisms that MPs establish with organic pollutants are still growing, which is essential to understand the adsorption properties of MPs and their relative stability with adsor-bates. Here, we used classical (force field methods) and ab-initio (density functional theory) computational chemistry tools to characterize the interaction mechanisms between Polystyrene-MPs (PS-MPs) and pharmaceuticals/personal care products (PPCPs). Adsorption conformations and energies, thermochemistry, binding, and energy decomposition analyses were performed to obtain the quantitative mechanistic information. Our results show that PS-MPs have per-manent dipoles, increasing the interaction with neutral PPCPs while repelling the charged pollutants; in all cases, a sta-ble physisorption takes place. Moreover, PS-MPs increase their solubility upon pollutant adsorption due to an increase in the dipole moment, increasing their co-transport ability in aqueous environments. The stability of the PS-MPs/ PPCPs complexes is further confirmed by thermochemical and molecular dynamics trajectory analysis as a function of temperature and pressure. The interaction mechanism of high pKa pollutants (pKa > 5) is due to a balanced contri-bution of electrostatic and dispersion forces, while the adsorption of low pKa pollutants (pKa < 5) maximizes the elec-trostatic forces, and steric repulsion effects explain their relative lower adsorption stability. In this regard, several pairwise intermolecular interactions are recognized as a source of stabilization in the PS-MPs/PPCPs binding: hydro-gen bonding, pi-pi, O\\HMIDLINE HORIZONTAL ELLIPSIS pi, and C\\HMIDLINE HORIZONTAL ELLIPSIS pi, C\\ClMIDLINE HORIZONTAL ELLIPSISC\\H and C\\HMIDLINE HORIZONTAL ELLIPSISC\\H interactions. The ionic strength in solution slightly affects the adsorption stability of neutral PPCPs, while the sorption of charged pollutants is enhanced. This mechanistic information provides quantitative data for a better understanding of the interactions between organic pol-lutants and MPs, serving as valuable information for sorption/kinetic studies.