scholarly journals Flexible Screen Printed Aptasensor for Rapid Detection of Furaneol: A Comparison of CNTs and AgNPs Effect on Aptasensor Performance

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1167
Author(s):  
Ali Douaki ◽  
Biresaw Demelash Abera ◽  
Giuseppe Cantarella ◽  
Bajramshahe Shkodra ◽  
Asma Mushtaq ◽  
...  

Furaneol is a widely used flavoring agent, which can be naturally found in different products, such as strawberries or thermally processed foods. This is why it is extremely important to detect furaneol in the food industry using ultra-sensitive, stable, and selective sensors. In this context, electrochemical biosensors are particularly attractive as they provide a cheap and reliable alternative measurement device. Carbon nanotubes (CNTs) and silver nanoparticles (AgNPs) have been extensively investigated as suitable materials to effectively increase the sensitivity of the biosensors. However, a comparison of the performance of biosensors employing CNTs and AgNPs is still missing. Herein, the effect of CNTs and AgNPs on the biosensor performance has been thoughtfully analyzed. Therefore, disposable flexible and screen printed electrochemical aptasensor modified with CNTs (CNT-ME), or AgNPs (AgNP-ME) have been developed. Under optimized conditions, CNT-MEs showed better performance compared to AgNP-ME, yielding a linear range of detection over a dynamic concentration range of 1 fM–35 μM and 2 pM–200 nM, respectively, as well as high selectivity towards furaneol. Finally, our aptasensor was tested in a real sample (strawberry) and validated with high-performance liquid chromatography (HPLC), showing that it could find an application in the food industry.

2019 ◽  
Vol 102 (5) ◽  
pp. 1316-1329 ◽  
Author(s):  
Tairo Ogura ◽  
Robert Clifford ◽  
Uwe Oppermann

Abstract Food allergy is a major concern for public health and food industries. Because of the large numbers of food ingredients to be tested, MS is considered an alternative to existing techniques in terms of high selectivity, sensitivity, and capability to analyze multiple allergens simultaneously. In this study, we developed the method for monitoring significant peptides derived from 13 food allergens (milk, eggs, cod, shrimp, lobster, almonds, brazil nuts, cashew nuts, hazelnuts, walnuts, peanuts, wheat, and soybeans) and evaluated it in thermally processed foods (bread, cookie, fried fish, and frozen pasta). To select significant peptides to monitor, we used a bioinformatics-based approach and experimental confirmatory analysis. It was demonstrated that the developed method could detect target food ingredients from thermally processed foods successfully.


Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3734 ◽  
Author(s):  
Jiaqi Shi ◽  
Zeping Shao ◽  
Honglei Li ◽  
Yan Zhang ◽  
Shuo Wang

Acrylamide and 5-hydroxymethyl-2-furfural (5-HMF) are two of the most abundant compounds generated during thermal processing. A simple method for the simultaneous quantitation of acrylamide and 5-HMF was developed and successfully applied in thermally processed foods. Acrylamide and 5-HMF were co-extracted with methanol and then purified and enriched by an Oasis HLB solid-phase extraction cartridge, simultaneously analyzed by high-performance liquid chromatography and detected with a diode array detector, respectively, at their optimal wavelength. The linear concentration range was found to be 25–5000 μg/L with high linear correlation coefficients (R > 0.999). The limit of detection and the limit of quantitation for acrylamide and 5-HMF were 6.90 μg/L and 4.66 μg/L, and 20.90 μg/L and 14.12 μg/L, respectively. The recovery of acrylamide and 5-HMF in biscuits, bread, Chinese doughnuts, breakfast cereals, and milk-based baby foods was achieved at 87.72–96.70% and 85.68–96.17% with RSD at 0.78–3.35% and 0.55–2.81%, respectively. The established method presents simplicity, accuracy and good repeatability, and can be used for the rapid simultaneous quantitation of acrylamide and 5-HMF in thermally processed foods.


2021 ◽  
Author(s):  
Naeime Salandari-Jolge ◽  
Ali A. Ensafi ◽  
Behzad Rezaei

Dipyridamole is a prescribed medication used to treat cardiovascular diseases, angina pectoris, imaging tests for heart patients, and myocardial infarction. Therefore, high selectivity and sensitivity, low cost, and high-performance speed...


Synlett ◽  
2020 ◽  
Author(s):  
Minyan Wang ◽  
Zhuangzhi Shi ◽  
Huanhuan Luo ◽  
Dawei Wang

AbstractOrganophosphines are an important class of ligands widely used in organic chemistry. Although great progress has recently been made in the rapid construction of new phosphines through Rh- or Ru-catalyzed C–H bond functionalizations, synthetic access to more diverse phosphines remains a challenge. We describe an efficient process for the rhodium-catalyzed phosphorus(III)-directed hydroarylation of internal alkynes to generate various alkenylated and 2′,6′-dialkenylated biarylphosphines with high selectivity. A range of diverse alkynes and phosphines were effectively prepared with broad functional-group compatibility under the optimized conditions. In addition, the developed protocol can be extended to modify chiral phosphine ligands, providing enantioenriched alkenylated phosphines without erosion of the enantiomeric excess.


2021 ◽  
Author(s):  
Feng Gao ◽  
Xiaolong Tu ◽  
Yongfang Yu ◽  
Yansha Gao ◽  
Jin Zou ◽  
...  

Abstract Herein, an efficient electrochemical sensing platform is proposed for selective and sensitive detection of nitrite on the basis of Cu@C@Zeolitic imidazolate framework-8 (Cu@C@ZIF-8) heterostructure. Core-shell Cu@C@ZIF-8 composite was synthesized by pyrolysis of Cu-metal-organic framework@ZIF-8 (Cu-MOF@ZIF-8) in Ar atmosphere on account of the difference of thermal stability between Cu-MOF and ZIF-8. For the sensing system of Cu@C@ZIF-8, ZIF-8 with proper pore size allows nitrite diffuse through the shell, while big molecules cannot, which ensures high selectivity of the sensor. On the other hand, Cu@C as electrocatalyst promotes the oxidation of nitrite, thereby resulting high sensitivity of the sensor. Accordingly, the Cu@C@ZIF-8 based sensor presents excellent performance for nitrite detection, which achieves a wide linear response range of 0.1 µM to 300.0 µM, and a low limit of detection (LOD) of 0.033 µM. In addition, the Cu@C@ZIF-8 sensor possesses excellent stability and reproducibility, and was employed to quantify nitrite in sausage samples with recoveries of 95.45-104.80%.


2020 ◽  
Author(s):  
Naoyuki Harada ◽  
Yoichi Sasaki ◽  
Masanori Hosoyamada ◽  
Nobuo Kimizuka ◽  
Nobuhiro Yanai

Until now, the efficiency of triplet-triplet annihilation-based photon upconversion (TTA-UC) from visible to ultraviolet (UV) light has been limited to ca. 10% due to the absence of high-performance acceptors (emitters). Here, we present the first example of visible-to-UV TTA-UC internal efficiency <i>η</i><sub>UC</sub> beyond 20% by developing a novel UV emitter, 1,4-bis((triisopropylsilyl)ethynyl)naphthalene (TIPS-Nph), and sensitizing its triplet by a donor Ir(C6)<sub>2</sub>(acac) with strong visible absorption and weak UV absorption. Under optimized conditions, 97% of the excitation light is absorbed, the threshold excitation intensity (<i>I</i><sub>th</sub> = 1.1 mW cm<sup>−2</sup>) is lower than the solar irradiance (1.4 mW cm<sup>−2</sup> for 445 ± 5 nm), and significantly, the highest external UC efficiency <i>η</i><sub>UC,ext</sub> of 17.4% for vis-to-UV TTA-UC is achieved. Upconverted UV emission can also be obtained with weak light sources such as an AM 1.5 solar simulator and room LEDs, paving the way for a variety of solar and indoor applications.


2021 ◽  
Vol 16 ◽  
pp. 1-9
Author(s):  
Muhammad Abdurrahman Munir ◽  
Muhammad Mukram Mohamed Mackeen ◽  
Lee Yook Heng ◽  
Khairiah Haji Badri

Histamine is a heterocyclic amine shaped by decarboxylation of the histidine. It is a compound that lack chromophore and involatile. However, the detection of histamine is imperative due to the characteristic of histamine has given several disadvantages in food industry. This paper describes methods for histamine detection by employing high performance liquid chromatography and gas chromatography. The derivatization techniques required for both methods in order to increase the sensitivity of chromatography analysis. Two derivatizing agents were applied in this study such as 9-flourenilmethyl chloroformate (FMOC – Cl) for HPLC analysis whereas for GC analysis a N,O-bis (trimethylsilyl)acetamide (BSA) was used. Method validation was in accordance to Commission Decision 657/2002/CE. The validation of specificity, linearity, precision, accuracy, detection limit and quantitation limit results indicate that the methods were acceptable. The linear range for both methods were at 0.16 – 5.00 µg∙mL-1. The determination of histamine using GC showed the superiority of this instrument compared to HPLC. Method applicability was also checked on real sample namely mackerel in order to acquire a satisfactory recovery for both methods.


Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 792
Author(s):  
Nurul Izzah Khalid ◽  
Nurul Shaqirah Sulaiman ◽  
Norashikin Ab Aziz ◽  
Farah Saleena Taip ◽  
Shafreeza Sobri ◽  
...  

Electrolyzed water (EW) shows great potential as a green and economical sanitation solution for the food industry. However, only limited studies have investigated the optimum electrolysis parameters and the bactericidal effect of acidic electrolyzed water (AcEW) and alkaline electrolyzed water (AlEW). Here, the Box–Behnken experimental design was used to identify the optimum parameters. The tests were conducted with different types of electrodes, electrical voltages, electrolysis times, and NaCl concentrations. There were no obvious differences observed in the physico-chemical properties of EW when different electrodes were used. However, stainless steel was chosen as it meets most of the selection criteria. The best-optimized conditions for AcEW were at 11.39 V, 0.65 wt.% NaCl, and 7.23 min, while the best-optimized conditions for AlEW were at 10.32 V, 0.6 wt.% NaCl, and 7.49 min. The performance of the optimum EW (AcEW and AlEW) compared with commercial cleaning detergents for the food industry was then evaluated. The bactericidal activity of AcEW and AlEW was examined against Escherichia coli ATCC 10536 at different temperatures (30 °C and 50 °C) for 30 s. The results show that both AcEW and AlEW have the ability to reduce the Escherichia coli to non-detectable levels (less than 2 log CFU/mL).


Sign in / Sign up

Export Citation Format

Share Document