scholarly journals Recent Advances in the Aptamer-Based Electrochemical Biosensors for Detecting Aflatoxin B1 and Its Pertinent Metabolite Aflatoxin M1

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3256 ◽  
Author(s):  
Hadi Beitollahi ◽  
Somayeh Tajik ◽  
Zahra Dourandish ◽  
Kaiqiang Zhang ◽  
Quyet Van Le ◽  
...  

The notable toxicological impacts of aflatoxin B1 (AFB1) and its main metabolite, aflatoxin M1 (AFM1), on human being health make the evaluation of food quality highly significant. Due to the toxicity of those metabolites—even very low content in foodstuffs—it is crucial to design a sensitive and reliable procedure for their detection. Electrochemical aptamer-based biosensors are considered the most encouraging option, based on multi-placed analysis, rapid response, high sensitivity and specificity. The present review specifically emphasizes the potential utilization of the electrochemical aptasensors for determining the AFM1 and AFB1 with different electrodes.

2019 ◽  
Vol 9 (11) ◽  
pp. 2364 ◽  
Author(s):  
Yongmei Jia ◽  
Guohua Zhou ◽  
Peilian Liu ◽  
Zhiguo Li ◽  
Biao Yu

Aflatoxin B1 (AFB1) is one of the most frequently-found mycotoxins in contaminated food. As the content of mycotoxins is particularly low in food, the development of probes to detect AFB1 in foods with high sensitivity and selectivity is an urgent social need for the evaluation of food quality. Numerous techniques have been developed to monitor AFB1. Nevertheless, most of them require cumbersome, labor-consuming, and sophisticated instruments, which have limited their application. An aptamer is a single, short nucleic acid sequence that is capable of recognizing different targets. Owing to their unique properties, aptamers have been considered as alternatives to antibodies. Aptasensors are considered to be an emerging strategy for the quantification of aflatoxin B1 with high selectivity and sensitivity. In this review, we summarize recent developments in colormetric, electrochemical, SERS, and fluorescent aptasensors for the quantification of AFB1. Finally, the perspectives and current challenges of aptasensors for AFB1 are outlined.


2010 ◽  
Vol 48 (08) ◽  
Author(s):  
A Rosenthal ◽  
H Köppen ◽  
R Musikowski ◽  
R Schwanitz ◽  
J Behrendt ◽  
...  

Aflatoxin M1 is one of mycotoxin derivatives, which is secreted in milk of dairy cattle fed on feed contaminated with Aflatoxin-B1 (AFB1). The current study was designed to prepare a vaccine against AFB1and to evaluate its efficacy in reducing or preventing secretion of AFM1 in milk. Aflatoxin-B1 was prepared, purified and transformed into oxime, then it was fixed on bovine serum albumins. The AFB1-BSA conjugate was adjuvanted with Gold Nano particles then Montanide ISA 206. The prepared vaccine was used for immunization of rabbits by S/c routes as 100 µg/dose and dairy cattle by I/M routes as 500 µg/dose. The vaccinated animals were boosted at 3 weeks post primary immunization. Serum samples were collected and examined for the anti-AFB1 using AGPT. A mean titer of 15.2 AGPU/ml was detected at 2 weeks post primary vaccination then significantly increased till reached to 76.8 AGPU/ml at 6 weeks post Booster vaccination. All vaccinated rabbits were challenged with dose of 0.3 mg AFB1 toxin/Kg. The vaccinated rabbit showed 100% protection and no AFB1 toxin residue was detected in their livers. Milk samples were collected from non-vaccinated and AFB1-immunized dairy cattle then examined with ELISA for quantitation of AFM1 residues before and after vaccination. The results showed that the prepared AFB1 vaccine was safe, potent and able to reduce AFM1 release in milk of vaccinated heifers by 70%. So the vaccination of lactating animals with the AFB1vaccine might represent a valid tool for the prevention of AFM1 contamination of milk and dairy products.


2019 ◽  
Vol 26 (11) ◽  
pp. 1946-1959 ◽  
Author(s):  
Le Minh Tu Phan ◽  
Lemma Teshome Tufa ◽  
Hwa-Jung Kim ◽  
Jaebeom Lee ◽  
Tae Jung Park

Background:Tuberculosis (TB), one of the leading causes of death worldwide, is difficult to diagnose based only on signs and symptoms. Methods for TB detection are continuously being researched to design novel effective clinical tools for the diagnosis of TB.Objective:This article reviews the methods to diagnose TB at the latent and active stages and to recognize prospective TB diagnostic methods based on nanomaterials.Methods:The current methods for TB diagnosis were reviewed by evaluating their advantages and disadvantages. Furthermore, the trends in TB detection using nanomaterials were discussed regarding their performance capacity for clinical diagnostic applications.Results:Current methods such as microscopy, culture, and tuberculin skin test are still being employed to diagnose TB, however, a highly sensitive point of care tool without false results is still needed. The utilization of nanomaterials to detect the specific TB biomarkers with high sensitivity and specificity can provide a possible strategy to rapidly diagnose TB. Although it is challenging for nanodiagnostic platforms to be assessed in clinical trials, active TB diagnosis using nanomaterials is highly expected to achieve clinical significance for regular application. In addition, aspects and future directions in developing the high-efficiency tools to diagnose active TB using advanced nanomaterials are expounded.Conclusion:This review suggests that nanomaterials have high potential as rapid, costeffective tools to enhance the diagnostic sensitivity and specificity for the accurate diagnosis, treatment, and prevention of TB. Hence, portable nanobiosensors can be alternative effective tests to be exploited globally after clinical trial execution.


Author(s):  
Hala T. Salem ◽  
Eman A.S. Sabek

Aim and Objective: To estimate the relationship between Coronary Calcium Scoring (CCS)and presence of different degrees of obstructive coronary artery disease (CAD) to avoid unnecessary examinations and hence unnecessary radiation exposure and contrast injection. Background: Coronary Calcium Scoring (CCS) is a test uses x-ray equipment to produce pictures of the coronary arteries to determine the degree of its narrowing by the build-up of calcified plaques. Despite the lack of definitive data linking ionizing radiation with cancer, the American Heart Association supports widely that practitioners of Computed tomography Coronary Angiography (CTCA) should keep “patient radiation doses as low as reasonably achievable but consistent with obtaining the desired medical information”. Methods: Data obtained from 275 CTCA examinations were reviewed. Radiation effective doses were estimated for both CCS and CTCA, measures to keep it as low as possible were presented, CCS and Framingham risk estimate were compared to the final results of CTCA to detect sensitivity and specificity of each one in detecting obstructive lesions. Results: CCS is a strong discriminator for obstructive CAD and can with high sensitivity and specificity and correlates well with the degree of obstruction even more than Framingham risk estimate which has high sensitivity and low specificity. Conclusion: CCS helps reducing the effective radiation dose if properly evaluated to skip unnecessary CTCA if obstructive lesions was unlikely, and as a test does not use contrast material, harmful effect on the kidney will be avoided as most of coronary atherosclerotic patients have renal problems.


Diagnostics ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Nam-Yun Cho ◽  
Ji-Won Park ◽  
Xianyu Wen ◽  
Yun-Joo Shin ◽  
Jun-Kyu Kang ◽  
...  

Cancer tissues have characteristic DNA methylation profiles compared with their corresponding normal tissues that can be utilized for cancer diagnosis with liquid biopsy. Using a genome-scale DNA methylation approach, we sought to identify a panel of DNA methylation markers specific for cell-free DNA (cfDNA) from patients with colorectal cancer (CRC). By comparing DNA methylomes between CRC and normal mucosal tissues or blood leukocytes, we identified eight cancer-specific methylated loci (ADGRB1, ANKRD13, FAM123A, GLI3, PCDHG, PPP1R16B, SLIT3, and TMEM90B) and developed a five-marker panel (FAM123A, GLI3, PPP1R16B, SLIT3, and TMEM90B) that detected CRC in liquid biopsies with a high sensitivity and specificity with a droplet digital MethyLight assay. In a set of cfDNA samples from CRC patients (n = 117) and healthy volunteers (n = 60), a panel of five markers on the platform of the droplet digital MethyLight assay detected stages I–III and stage IV CRCs with sensitivities of 45.9% and 95.7%, respectively, and a specificity of 95.0%. The number of detected markers was correlated with the cancer stage, perineural invasion, lymphatic emboli, and venous invasion. Our five-marker panel with the droplet digital MethyLight assay showed a high sensitivity and specificity for the detection of CRC with cfDNA samples from patients with metastatic CRC.


Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 384
Author(s):  
Shufeng Wang ◽  
Xin Yang ◽  
Feng Liu ◽  
Xinzheng Wang ◽  
Xuemin Zhang ◽  
...  

Hepatitis B virus (HBV) infection and aflatoxin B1 (AFB1) exposure have been recognized as independent risk factors for the occurrence and development of hepatocellular carcinoma (HCC), but their combined impacts and the potential metabolic mechanisms remain poorly characterized. Here, a comprehensive non-targeted metabolomic study was performed following AFB1 exposed to Hep3B cells at two different doses: 16 μM and 32 μM. The metabolites were identified and quantified by an ultra-performance liquid chromatography-mass spectrometry (UPLC-MS)-based strategy. A total of 2679 metabolites were identified, and 392 differential metabolites were quantified among three groups. Pathway analysis indicated that dynamic metabolic reprogramming was induced by AFB1 and various pathways changed significantly, including purine and pyrimidine metabolism, hexosamine pathway and sialylation, fatty acid synthesis and oxidation, glycerophospholipid metabolism, tricarboxylic acid (TCA) cycle, glycolysis, and amino acid metabolism. To the best of our knowledge, the alteration of purine and pyrimidine metabolism and decrease of hexosamine pathways and sialylation with AFB1 exposure have not been reported. The results indicated that our metabolomic strategy is powerful to investigate the metabolome change of any stimulates due to its high sensitivity, high resolution, rapid separation, and good metabolome coverage. Besides, these findings provide an overview of the metabolic mechanisms of the AFB1 combined with HBV and new insight into the toxicological mechanism of AFB1. Thus, targeting these metabolic pathways may be an approach to prevent carcinogen-induced cancer, and these findings may provide potential drug targets for therapeutic intervention.


2021 ◽  
Vol 93 (5) ◽  
pp. 2950-2958
Author(s):  
Valério G. Barauna ◽  
Maneesh N. Singh ◽  
Leonardo Leal Barbosa ◽  
Wena Dantas Marcarini ◽  
Paula Frizera Vassallo ◽  
...  

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