Antibody conjugated magnetic nanoparticle based colorimetric assay for the detection and quantification of aflatoxin B1 in wheat grains

2021 ◽  
pp. 1-16
Author(s):  
R. Kumari ◽  
H. Jaiswal ◽  
T. Chowdhury ◽  
A.K. Ghosh

Aflatoxin B1 (AFB1) is a most potent carcinogenic secondary metabolite produced by Aspergillus flavus. As a food safety concern, development of a rapid, cost effective, sensitive and easy to use method for the detection of aflatoxin is of prime requirement. In this study, AFB1 was conjugated with bovine serum albumin (BSA), and AFB1-BSA conjugate was purified by HPLC. Purification was confirmed by UV-Vis spectroscopy, FTIR and MALDI-TOF mass spectrometry. The polyclonal antibody was raised against AFB1-BSA conjugate in rabbit and purified by protein A sepharose and BSA sepharose affinity columns. Iron oxide nanoparticles (MNPs) were synthesised by co-precipitation method and their surface was functionalised with (3-aminopropyl) triethoxysilane (APTES). Size of APTES conjugated MNPs was determined by electron microscopy, and characterised by several biophysical techniques. The purified anti-AFB1 antibody was conjugated with surface functionalised MNPs and the conjugation was confirmed by determining the sizes of free and antibody conjugated MNPs by field emission scanning electron microscope where increase of particle sizes from 10-20 to 40-50 nm was observed due to antibody conjugation. Anti-AFB1 antibody conjugated MNPs were used for capturing AFB1 from the aflatoxin spiked wheat grains with a recovery percentage of more than 80% and used effectively five times. The captured AFB1 was then quantified by a sensitive colorimetric assay where colourless AFB1 was first converted into coumaric acid by NaOH. Subsequently, coumaric acid reacted with 2,6-dibromoquinone-4-chloroimide (DBQC) to a green-coloured indophenol product which was quantified spectrophotometrically. AFB1 contamination as low as 2 μg/kg in wheat grains was detected by the developed technique suggesting its potential application for both qualitative and quantitative analysis of aflatoxins present in feed and food materials.

2021 ◽  
Author(s):  
Qiushi Jiang ◽  
Zhaolian Han ◽  
Yafeng Yuan ◽  
Zhiqiang Cheng

Abstract In this study, CaO prepared by calcination treatment from abandoned Achatina fulica shell was used as a raw material, and the nano-flower-like CaO/ZnO photocatalytic composite material was prepared through co-precipitation method. SEM study showed ZnO with spindle-like petals in the range of 500-1000 nm grown on the surface of CaO carrier. The mapping image shows that the base component of the nanometer flower is mainly CaO, which is because CaO is not only in the reaction as a carrier, but also creates an alkaline environment in the methanol system, which is advantageous for co-precipitation. UV-vis spectroscopy shows that the visible light absorption of composites has red shifts, besides, PL, EIS and photocurrent test showed that the composites have stronger electronic hole separation capabilities. The visible light degradation test of rhodamine B showed that CaO/ZnO photocatalytic composite could degrade 90% of the pollutants in 25 min, superior to CaO and ZnO, exhibiting recyclability properties, which is a potential candidate with cost-effective and sustainable photocatalysts.


2021 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Muhammad Nur Iman Amir ◽  
Nurhidayatullaili Muhd Julkaplia ◽  
Saba Afzal

Titanium dioxide (TiO2) nanoparticles are used enormously for treating wastewater pollutants due to their unique optoelectronic and physiochemical properties. Though, wide bandgap, fast recombination of e- - h+ pair, and low adsorption toward organic pollutants limit their applications. However, immobilization of TiO2 on Chitosan (Cs) is believed to overcome these limitations. Cs with plenty of NH2 and OH groups in their structure are expected to enhance their adsorption and consequently photocatalytic performance. A series of TiO2/Cs photocatalysts have been prepared using a chemical co-precipitation method. Amount of TiO2 is varied from 0.25, 0.50, and 0.75 to 1.0 g. The photocatalysts are characterized by using FESEM-EDS, CHNS Elemental Analyser TGA, FTIR, and UV-Vis spectroscopy. These characterization results revealed the formation of a good interface between TiO2 and Cs matrix. Increasing TiO2 content significantly increased the thermal stability of the photocatalyst up to 600ᵒC. The photocatalytic activity of Cs/TiO2 is observed under UV light which is found to be more significant with 1:1(TiO2: Cs) composition for the degradation of methylene blue dye at 85 % and be maintained up to 4 numbers of cycles. This demonstrated open new insight into the application of Cs as a support materials and adsorption agent in TiO2 based photocatalyst system


2014 ◽  
Vol 879 ◽  
pp. 155-163 ◽  
Author(s):  
Rahizana Mohd Ibrahim ◽  
Markom Masturah ◽  
Huda Abdullah

Nanoparticles of Zn1-xFexS ( x=0.0,0.1,0.2 and 0.3) were prepared by chemical co-precipitation method from homogenous solution of zinc and ferum salt at room temperature with controlled parameter. These nanoparticles were sterically stabilized using Sodium Hexamethaphospate (SHMP). Here, a study of the effect of Fe doping on structure, morphological and optical properties of nanoparticles was undertaken. Elemental analysis, morphological and optical properties have been investigated by Fourier-Transform-Infrared spectroscopy (FT-IR), X-Ray Fluorescence (XRF), Field Emmision Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and UV-Visible Spectroscopy. FTIR measurement confirmed the presence of SHMP in the nanoparticles structure with the FESEM images depicting considerable less agglomeration of particles with the presence of SHMP. While XRF results confirm the presence of Fe2+ ion as prepared in the experiment. The particles sizes of the nanoparticles lay in the range of 2-10 nm obtained from the TEM image were in agreement with the XRD results. The absorption edge shifted to lower wavelengths with an increase in Fe concentration shown in the UV-Vis spectroscopy. The band gap energy value was in the range of 4.95 5.15 eV. The blueshift is attributed to the quantum confinement effect.


2019 ◽  
Vol 16 (2) ◽  
pp. 174-182
Author(s):  
M. Sathish Kumar ◽  
M. Saroja ◽  
M. Venkatachalam

The development of biomedical electronics, biosynthesis of ZnS nanoparticles(NPs) much attracted researchers, due to an eco-friendly and cost-effective routes forsynthesisZnSnanoparticles. In this present work, ZnS NPswas synthesized by using acalypha indica and curcuma longa plant extract using chemical co-precipitation method. The structural, morphological, element composition of biosynthesisZnS NPs was characterized by XRD, SEM and EDAX respectively. Optical and photoluminescence (PL) properties were evaluated by UV Visible spectroscopy. The formation of inhibition zone diameter against human pathogenic microorganisms was screened by in vitro disc diffusion method. From this investigation formation of inhibition zones clearly shows biosynthesizedZnS NPs have high antimicrobial activity against tested organisms, especially curcuma longa plant extract mediated ZnS NPs was formed maximum inhibition against all the tested microorganism.


2019 ◽  
Vol 2 (3) ◽  
pp. 1233-1237
Author(s):  
Yekbun Avşar Teymur ◽  
Fuat Güzel ◽  
Gülbahar Akkaya Sayğılı

In this study, the synthesis and characterization of a biomagnetic composite material was achieved by a simple and cost effective method. Tomato processing waste was successfully converted into a magnetic material via embedding Fe3O4 nanoparticles to its structure. Due to its low cost and ease of application, co-precipitation method was used for loading the magnetite nanoparticles. Characterization studies were carried out with Fourier transform infrared spectroscopy, scanning electron microscopy and vibrating sample magnetometer spectroscopy and the outcomes of the analyses of non-magnetic and magnetic material were compared.


2021 ◽  
Vol 1162 ◽  
pp. 41-46
Author(s):  
Uripto Trisno Santoso ◽  
Abdullah ◽  
Dwi Rasy Mujiyanti ◽  
Dahlena Ariyani ◽  
Joyo Waskito

Reverse co-precipitation (RCP) in ambient atmosphere is one of the strategies to produce magnetite nanoparticles in a rapid, simple, and cost-effective synthesis route without applying temperature surfactants or inert gases. However, RCP of ferrous/ferric blended salt in sodium hydroxide (NaOH) solution in an oxidizing medium produced of maghemite as a dominant phase rather than magnetite because of the oxidation of Fe2+ to Fe3+ happened. Based on this background, an oil membrane layer-assisted reverse co-precipitation approach has been examined to synthesis of magnetite in ambient atmosphere at room temperature. The result showed that although addition of benzene as an oil membrane layer was effective to prevent oxidation of magnetite to maghemite, but the magnetite particle size for the samples from the oil membrane layer-assisted reverse co-precipitation method was much larger than that from a reverse co-precipitation method without addition of oil membrane layer.


2013 ◽  
Vol 319 ◽  
pp. 209-212 ◽  
Author(s):  
Shu Qiong Kong ◽  
Yan Xin Wang ◽  
Cheng Wang ◽  
Li Ling Jin ◽  
Ming Liang Liu ◽  
...  

Cost-effective technologies to remove arsenic from high arsenic groundwater are urgently needed for safe water supply in many countries. In this study, a new sorbent of nanoscale iron-manganese binary oxides (NIM) was prepared by an improved co-precipitation method. The as-synthesized adsorbent is amorphous with 280 m2/g surface area and particle size of 10-20nm. For the adsorption of 2 mg/L As(III), the aqueous concentration quickly decreases to less than 10 μg/L within 30 min. During the adsorption of As(III), low concentration of As(V) is measured in aqueous solution in the initial stage and disappeared afterwards, whereas the fraction of As(V) on NIM surface gradually proving the oxidative transformation of As(III) to As(V). Its batch experiment data followed pseudo-second-order kinetics.


2017 ◽  
Vol 19 (31) ◽  
pp. 20541-20550 ◽  
Author(s):  
Virendrakumar G. Deonikar ◽  
Santosh S. Patil ◽  
Mohaseen S. Tamboli ◽  
Jalindar D. Ambekar ◽  
Milind V. Kulkarni ◽  
...  

We demonstrate a simple, cost effective co-precipitation method to synthesize APO/LCO heterostructures and investigate the effect of a mixed solvent system (H2O:THF) on the growth of microstructures.


2018 ◽  
Vol 16 (5) ◽  
pp. 846-856 ◽  
Author(s):  
V. Sabna ◽  
Santosh G. Thampi ◽  
S. Chandrakaran

Abstract This is an investigation on oxidative degradation of rhodamine B (RhB) by manganese dioxide (MnO2) nanorods synthesized by redox co-precipitation method. Field emission scanning electron microscopy of MnO2 nanorods at an electron voltage of 10 kV revealed a rod-like morphology for the synthesized nanoparticles. Fourier transform infrared spectra exhibited characteristic peaks of MnO2. Surface area of MnO2 nanorods was 277 m2/g. Effect of various parameters like initial concentration and pH of RhB solution, time of contact between MnO2 nanorods and RhB, dosage of MnO2, and stirring speed on decolouration of RhB was evaluated in batch experiments. Rapid decolouration in the initial period of the reaction was observed due to the adsorption of RhB molecules onto the surface of MnO2 nanorods followed by oxidative degradation. Percentage decolouration decreased with increase in initial concentration and increased with increase in dosage, speed of stirring the mixture and with increase in pH up to pH 7. Near complete decolouration was achieved at a dose of 0.5 g/L of MnO2 nanorods from 20 mg/L RhB solution within 3 min. Observations fitted best to the pseudo second order kinetic model. This study could pave the way for development of cost-effective, nontoxic nanostructures for treatment of wastewaters containing RhB.


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