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  • br Also as presented in Fig the

    2019-10-01


    Also, as presented in Fig. 7, the peak currents of catechol on the biosensor are linearly related to the logarithm of the concentrations of the target DNA and the CEA antigen in the ranges of 10 pM to 100 μM and 1 pg mL−1 to 0.001 g mL−1 with the detection limits of 1.5 pM and 0.26 pg mL−1 respectively.
    This result (detection limits of 0.26 pg mL−1 for the CEA antigen) is almost a good result, versus the Cell Biolabs ELISA kits (Catalog 
    Numbers PRB- 5059) result with the detection sensitivity of 150 pg mL−1 for CEA, and the Thermo Scientific™ Human CEA ELISA Kit (EHCEA) result with the analytical sensitivity of 200 pg mL−1 for CEA.
    3.7. Performance with patient samples
    To investigate the simultaneous presence of BCR/ABL fusion gene and CEA in real-life samples of acute lymphoblastic leukemia patients, real-life samples were extracted from the human blood (the sample collection is offered in partnership with the Khatam Al-Anbia Super Speciality Clinic).
    At current work, a Elafibranor (GFT505) targeting the BCR/ABL1 fusion gene in ALL patients was developed, hence, random blood samples were collected from 30 patients with acute lymphoblastic leukemia (the DNA sequence was collected from 500 μL blood samples of patients with ALL cancer).
    Subsequently, patient samples were denatured by heating at 95 °C for 7 min and then cooled down in an ice bath for 3 min. After that, 1 μL of a sample was diluted with 9 μL of a hybridization buffer [10]. Then, 2.5 μL of that sample was dropped on the surface of the modified electrode. The hybridization reaction was allowed to proceed for an optimum time, and then the biosensor was washed with the Tris-EDTA buffer solution.
    According to the results, there was an agreement in results of PCR investigations and the data recorded by biosensors.
    To study the presence of the carcinoembryonic antigen in samples of acute lymphoblastic leukemia patients, real-life samples were extracted from the human blood. After that, 1 μL of a sample was diluted with 9 μL of a hybridization buffer. Then, 2.5 μL of that sample was dropped on the surface of the modified electrode. Then this reaction was allowed to proceed for an optimum time, and then the biosensor was washed with the Tris-EDTA buffer solution.
    A DPV analysis was done in 2 mM of a catechol solution to study the hybridization process of the DNA strands and the attachment of the CEA to the aptamers, in patient samples. According to the results, there was a decrement in the DPV signal for the blood samples which were col-lected from ALL patients. This means that the attachment took place between the ssDNA and complementary real-life sample (patient sample) DNA as well as between the aptamer and the target antigen in real-life sample (patient sample) of acute lymphoblastic leukemia pa-tients (Fig. S11).
    4. Conclusion
    The purpose of this paper is to introduce a developed package of biosensors (a combination of a DNA sensor and an aptasensor) which can detect not only the presence of mutant genes but also the bio-markers of cancer. According to the results, we anticipate this scheme have potential to develop the system of biosensors for screening other kinds of cancers too.
    At current work, a positive test result of a DNA sensor generally means that a person has a mutant gene and that he or she is at the risk of a cancer; however, a positive test result of an aptasensor means that the person already has the disease (i.e. ALL cancer). In this regard, it should be noted that the concentration of biomarkers is used for the screening of cancer stages.
    Fig. 7. (a1) DPVs of the dsDNA/Bio AuNP/CD/GCE and (a2) the calibration curve of the dsDNA/Bio AuNP/CD/GCE at different concentrations of the target DNA in 2 mM of catechol in PBS. (b1) DPVs of the Anti/APTA/Bio AuNP/CD/GCE and (b2) the calibration curve of the Anti/APTA/Bio AuNP/CD/GCE at different con-centrations of the target DNA in 2 mM of catechol in PBS.