scholarly journals Ranolazine-Functionalized Copper Nanoparticles as a Colorimetric Sensor for Trace Level Detection of As3+

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 83 ◽  
Author(s):  
Gul Laghari ◽  
Ayman Nafady ◽  
Sameerah Al-Saeedi ◽  
Sirajuddin ◽  
Syed Sherazi ◽  
...  

This study involves environmentally friendly synthesis of copper nanoparticles in aqueous medium without inert gas protection, using ranolazine as a capping material. UV-Visible (UV-Vis) spectrometry showed that ranolazine-derived copper nanoparticles (Rano-Cu NPs) demonstrate a localized surface plasmon resonance (LSPR) band at 573 nm with brick-red color under optimized parameters, including pH, reaction time, and concentrations of copper salt, hydrazine hydrate, and ranolazine. The coating of ranolazine on the surface of Cu NPs was studied via Fourier transform infrared (FTIR) spectroscopy. Scanning electron microscopy (SEM) revealed that Rano-Cu NPs consist of spherical particles. X-ray diffraction (XRD) verified that Rano-Cu NPs are crystalline in nature. Atomic force microscopy (AFM) showed that the average size of Rano-Cu NPs was 40 ± 2 nm in the range of 22–95 nm. Rano-Cu NPs proved to be highly sensitive as a selective colorimetric sensor for As3+ via color change from brick red to dark green, in the linear range of 3.0 × 10−7 to 8.3 × 10−6 M, with an R² value of 0.9979. The developed sensor is simple, cost effective, highly sensitive, and extremely selective for As3+ detection, showing a low detection limit (LDL) of 1.6 × 10−8 M. The developed sensor was effectively tested for detection of As3+ in some water samples.

2020 ◽  
Vol 44 (5) ◽  
pp. 1376-1385 ◽  
Author(s):  
Roomia MEMON ◽  
Ayaz Ali MEMON ◽  
Syed Tufail Hussain SHERAZI ◽  
Sirajuddin Sirajuddin ◽  
Aamna BALOUCH ◽  
...  

The presented work demonstrates the preparation of copper nanoparticles (CuNPs) via aqueous leaves extract of Ziziphus mauritiana L. (Zm) using hydrazine as a reducing agent. Various parameters such as volume of extract, concentration of hydrazine hydrate, concentration of copper chloride, and pH of the solution were optimized to obtain Ziziphus mauritiana L. leaves extract derived copper nanoparticles (Zm-CuNPs). Brownish red color was initial indication of the formation of Zm-CuNPs while it was confirmed by surface plasmon resonance (SPR) band at wavelength of 584 nm using ultraviolet-visible (UV-vis) spectroscopy. Synthesized Zm-CuNPs were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffractometry (XRD). AFM images showed that the particle size of Zm-CuNPs was from 7 to 17 nm with an average size of 11.3 nm. Fabricated sensor (Zm-CuNPs) were used as a colorimetric sensor for the detection of Ag+ at a linear range between 0.67 × 10–6 – 9.3 × 10–6 with R2 value of 0.992. For real water samples, limit of quantification (LOQ) and limit of detection (LOD) for Ag+ was found to be 330 × 10–9 and 100 × 10–9, respectively.


Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1861 ◽  
Author(s):  
Abdelaziz Elgamouz ◽  
Hamid Idriss ◽  
Chahlaa Nassab ◽  
Alaa Bihi ◽  
Khalid Bajou ◽  
...  

A green and cost-effective technique for the preparation of silver nanoparticles (Algae-AgNPs) as a colorimetric sensor for hydrogen peroxide (H2O2) is described. Silver nanoparticles were capped using the green algae (Noctiluca scintillans) extract at an optimum time of 3 h at 80 °C. The pH of the plant extract (pH = 7.0) yields nanoparticles with a mean size of 4.13 nm and a zeta potential of 0.200 ± 0.02 mV and negative polarity, using dynamic light scattering (DLS). High-resolution transmission electron microscopy (HRTEM) analysis showed regular spherical particles with the average size of 4.5 nm. Selected area electron diffraction (SAED) results revealed the polycrystalline nature of the silver nanoparticles. The obtained patterns were indexed as (111), (200), (220), and (311) reflections of the fcc (face centered cubic) silver crystal based on their d-spacing of 2.47, 2.13, 1.49, and 1.27 Å, respectively. The apparent color change from brown to colorless was observed when nanoparticles reacted with H2O2. Linear responses were obtained in three different ranges (nM, µM, and mM). Limits of detection (LOD) of 1.33 ± 0.02 and 1.77 ± 0.02 nM and quantitation limits (LOQ) of 7.31 ± 0.03 and 9.67 ± 0.03 nM were obtained for Abs and ΔAbs calibration curves, respectively. 10% v/v Algae-AgNPs solution inhibited Staphylococcus aureus over Escherichia coli, while a 50% reduction of tumor cell growth of MDA-MB-231 human breast adenocarcinoma was obtained.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4364
Author(s):  
Rutaba Amjad ◽  
Bismillah Mubeen ◽  
Syed Shahbaz Ali ◽  
Syed Sarim Imam ◽  
Sultan Alshehri ◽  
...  

The use of biomaterials in the synthesis of nanoparticles is one of the most up-to-date focuses in modern nanotechnologies and nanosciences. More and more research on green methods of producing metal oxide nanoparticles (NP) is taking place, with the goal to overcome the possible dangers of toxic chemicals for a safe and innocuous environment. In this study, we synthesized copper nanoparticles (CuNPs) using Fortunella margarita leaves’ extract, which reflects its novelty in the field of nanosciences. The visual observation of a color change from dark green to bluish green clearly shows the instant and spontaneous formation of CuNPs when the phytochemicals of F. margarita come in contact with Cu+2 ions. The synthesis of CuNPs was carried out at different conditions, including pH, temperature, concentration ratio and time, and were characterized with UV-Vis absorption spectra, scanning electron microscope (SEM) and X-ray diffraction (XRD). The UV-Vis analysis reveals the surface plasmon resonance property (SPR) of CuNPs, showing a characteristic absorption peak at 679 nm, while SEM reveals the spherical but agglomerated shape of CuNPs of the size within the range of 51.26–56.66 nm.


2021 ◽  
Author(s):  
CI Chemistry International

In view of advantages of green synthesis, a novel green route for the synthesis and stabilization of copper nanoparticles (CuNPs) using aqueous extract of Citrus limon fruits at room temperature was reported. The formation of CuNPs is monitored by recording the UV–vis absorption spectra for surface Plasmon resonance (SPR) peak (∼579 nm). X-ray diffraction (XRD) pattern of the CuNPs agrees with the reported data for Cu metal and the crystallite average size is ~30 nm. Scanning and transmission electron microscopic (SEM and TEM) show uniform spherical particles obtained by this green method. The antimicrobial activity is found to be effective of CuNPs. Results revealed that the green synthesis is an efficient for the preparation of CuNPs as an active antimicrobial agent for practical applications.


2011 ◽  
Vol 117-119 ◽  
pp. 958-961 ◽  
Author(s):  
Jun Chen ◽  
Cai Xia Dong ◽  
Yi Jun Zhang ◽  
Xiao Mao Zhou ◽  
Lian Yang Bai

This paper reports a novel colorimetric sensor for pymetrozine based on p-aminobenzenesulfonic acid functionalized silver nanoparticles (p-ABSA-modified Ag NPs), which were characterized by IR spectroscopy, ultraviolet–visible spectroscopy (UV–vis), and transmission electron microscopy (TEM). The newly synthesized p-ABSA-modified Ag NPs are yellow in color due to the intense surface plasmon absorption band centered at 400nm. In the presence of pymetrozine, the yellow p-ABSA-modified Ag NPs solution turns to dark green, with a dramatic surface plasmon absorption band centered at 660nm. Moreover, high selectivity for pymetrozine was approved by the comparative experiments with an absorption ratio of A660/A400 more than 0.7. This highly sensitive sensor allows a direct and rapid quantitative assay of pymetrozine with a colorimetric limited detection concentration of 0.01mg/L.


Coatings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 38
Author(s):  
Jingyang Zhu ◽  
Lifeng Yin ◽  
Weiyi Zhang ◽  
Meilian Chen ◽  
Dongsheng Feng ◽  
...  

Deltamethrin (DEL) is one of the most commonly used pyrethroid pesticides that can cause serious harms to the ecological environment and human health. Herein, we have developed a paper-based colorimetric sensor impregnated with gold nanoparticles (AuNPs) for on-site determination of DEL pesticide. AuNPs show obvious color change on paper device with the presence of DEL. Measuring the gray intensity of the AuNPs on the reaction zone of the paper sensor allows accurate quantitative analysis. The detection mechanism of DEL on paper sensor was confirmed by UV-Vis spectrophotometry (UV-Vis), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscope (TEM). Under optimal conditions, the colorimetric sensor exhibited high sensitivity, rapid detection, and low detection limit within the values stipulated by Chinese detection standards (LOD = 0.584 mg/L). Besides, detecting DEL in vegetable and fruit samples also gave satisfying results, which were much consistent with those obtained by spectrophotometry. Overall, this work provided a user-friendly, cost-effective and visualized detection platform, which could be applied to rapidly detect DEL pesticides in the food safety field.


Chemosensors ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 334
Author(s):  
Krittapas Kaewnu ◽  
Kiattisak Promsuwan ◽  
Apichai Phonchai ◽  
Adul Thiangchanya ◽  
Dongsayam Somapa ◽  
...  

A novel foam-based colorimetric alcohol sensor was developed for the detection of alcohol in saliva. Detection was based on the color change of a potassium dichromate-sulfuric acid solution absorbed by melamine foam. In the presence of alcohol, the orange colorimetric sensor changed color to brown, green and, ultimately, blue, depending on the concentration of alcohol in the sample. The response of the proposed sensor toward alcohol was linear from 0.10 to 2.5% v/v. The limit of detection was 0.03% v/v. Alcohol concentration could be determined using the naked eye in the range of 0.00 to 10% v/v. The developed alcohol sensor presented good operational accuracy (RSD = 0.30–1.90%, n = 8) and good stability for 21 days when stored at 25 °C and 75 days when stored at 4 °C. The results of alcohol detection with the developed sensor showed no significant difference from the results of spectrophotometric detection at a 95% confidence level (p > 0.05). The sensor was easy to use, small, inexpensive and portable, enabling drivers to accurately measure their own blood alcohol level and providing convenient speed in forensic applications.


2018 ◽  
Vol 9 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Shubhangi J. Mane-Gavade ◽  
Sandip R. Sabale ◽  
Xiao-Ying Yu ◽  
Gurunath H. Nikam ◽  
Bhaskar V. Tamhankar

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1089
Author(s):  
Muhammad T. Sajjad ◽  
Ashu K. Bansal ◽  
Francesco Antolini ◽  
Eduard Preis ◽  
Lenuta Stroea ◽  
...  

Many displays involve the use of color conversion layers. QDs are attractive candidates as color converters because of their easy processability, tuneable optical properties, high photoluminescence quantum yield, and good stability. Here, we show that emissive QDs with narrow emission range can be made in-situ in a polymer matrix, with properties useful for color conversion. This was achieved by blending the blue-emitting pyridine based polymer with a cadmium selenide precursor and baking their films at different temperatures. To achieve efficient color conversion, blend ratio and baking temperature/time were varied. We found that thermal decomposition of the precursor leads to highly emissive QDs whose final size and emission can be controlled using baking temperature/time. The formation of the QDs inside the polymer matrix was confirmed through morphological studies using atomic force microscopy (AFM) and transmission electron microscopy (TEM). Hence, our approach provides a cost-effective route to making highly emissive color converters for multi-color displays.


Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 139
Author(s):  
Yan Wang ◽  
Ying Yan ◽  
Xinfa Liu ◽  
Changbei Ma

As an important DNA 3′-phosphatase, alkaline phosphatase can repair damaged DNA caused by replication and recombination. It is essential to measure the level of alkaline phosphatase to indicate some potential diseases, such as cancer, related to alkaline phosphatase. Here, we designed a simple and fast method to detect alkaline phosphatase quantitively. When alkaline phosphatase is present, the resulting poly T-DNA with a 3′-hydroxyl end was cleaved by exonuclease I, prohibiting the formation of fluorescent copper nanoparticles. However, the fluorescent copper nanoparticles can be monitored with the absence of alkaline phosphatase. Hence, we can detect alkaline phosphatase with this turn-off strategy. The proposed method is able to quantify the concentration of alkaline phosphatase with the LOD of 0.0098 U/L. Furthermore, we utilized this method to measure the effects of inhibitor Na3VO4 on alkaline phosphatase. In addition, it was successfully applied to quantify the level of alkaline phosphatase in human serum. The proposed strategy is sensitive, selective, cost effective, and timesaving, having a great potential to detect alkaline phosphatase quantitatively in clinical diagnosis.


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