Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2025Scopus SJRQ2/r/munzur/1207
  Highly sensitive DNA-based electrochemical biosensor for analysis of oseltamivir used in treatment of COVID–19

  Keçeci, Ali; Koçak, Berna; İpek, Yeliz

  Promising clinical results were obtained in the treatment of coronavirus disease by using favipiravir, umifenovir, remdesivir, ribavirin, lopinavir–ritonavir, oseltamivir, etc., antiviral drug active agents. In this study, quantitative analysis of oseltamivir neuraminidase inhibitor was carried out using electrochemical techniques. DNA-based electrochemical biosensors are generally used for analysis of anticancer and antitumor medicines. The present study introduces a novel DNA-based electrochemical sensor for neuraminidase inhibitor drug oseltamivir. The developed sensor enables the analysis of oseltamivir in a more environmentally friendly, more economical and faster way. It can be used in quality control laboratories in tablet production and will provide traceability of the drug in drug development studies and analysis in urine samples. For this purpose, a modified glassy carbon electrode was used as a working electrode. The glassy carbon electrodes alone cannot detect the oseltamivir. Guanine base, which was determined to interact with oseltamivir and found in the deoxyribonucleic acid structure, was used as an electrochemical biosensor agent. The guanine base was immobilized on glassy carbon electrode using glutardialdehyde as a crosslinker material and GA2–Guanine/GCE electrode was achieved. Two working ranges were determined for the Britton-Robinson buffer solution, tablet sample, and urine sample containing oseltamivir. The lowest detection limits (LODs) were calculated as 7.16 × 10−9 mol L−1, 9.05 × 10−9 mol L−1 and 6.19 × 10−6 mol L−1 for Britton-Robinson buffer solution, tablet sample solution, and urine sample solution, respectively. The recovery ratio for the proposed sensor ranged between 86.6 and 103.5%.

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  AtıfScopus3·WoS3·OpenAlex3

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• MakaleYalnız künye2025Scopus SJRQ3/r/munzur/968
  Eco-Friendly and Practical Electrochemical Determination of Lactic Acid in Milk Using Boron Doped Diamond Electrode

  İpek, Yeliz.; Koçak, Berna; Keçeci, Ali

  In this study, an economical, environmentally friendly, sensitive, selective, and rapid voltammetric quantitative analysis method was developed using a boron doped diamond electrode to determine lactic acid (LA). Two linear working ranges were determined for LA determination in phosphate buffer solution (PBS, pH of 2). The first linear working range (LR1) was between concentrations of 1.5 × 10−6–8 × 10−6 mol· L−1, with a detection limit of 1.3 × 10−6 mol·L−1, and the limit of quantification (LOQ) was found to be 4.4 µmol· L−1. The second linear working range (LR2) was determined in the concentration range of 8.0–89.2 µmol·L−1. LOD was calculated as 15.8 µmol·L−1, and the LOQ value was calculated as 52.6 µmol·L−1 in the LR2. Intraday repeatability of the BDD electrode for LA determination was (RSD) 6.8% in LR1 and 11.8% in LR2. The interday repeatabilities of the BDD electrode in LR1 and LR2 were calculated as 7.7% and 4.7%, respectively. The developed electrochemical sensor was successfully applied for the determination of LA in milk sample. The sensor exhibited a short response time of about 10 s in PBS at pH 2. The recovery values of LA in PBS and milk sample were 97.3% and 96.1%, respectively.

  AtıfScopus2·WoS2·OpenAlex2

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• Yüksek Lisans TeziAçık Erişim2023/r/munzur/6924
  Covıd‒19 tedavisinde kullanılan oseltamivir ilaç etken maddesinin DNA biyosensörü ile elektrokimyasal analizi

  Ali Keçeci

  COVID–19 tedavisi için çeşitli antiviral ilaçlar kullanılmaktadır ve çeşitli ilaçlar araştırılmaktadır. Favipiravir (FAV), alfa–interferon, umifenovir, remdesivir (RMD), ribavirin, lopinavir (LPV)–ritonavir, oseltamivir (OST) vb. ilaç etken maddeleri kullanılarak COVID–19 için umut verici klinik sonuçlar elde edilmiştir. Bu çalışmada COVID‒19 tedavisinde kullanılan ilaç etken maddesi OST'nin elektrokimyasal teknikler kullanılarak, kantitatif analizi gerçekleştirilmiştir. Böylece ilaç üretim aşamalarında ilaç dozunun kalite kontrolü ve etken maddenin idrarla atılımını takip edip ilaç tasarımı çalışmalarında kullanılabilecek bir elektrokimyasal sensör geliştirilmiştir. Bu amaçla camsı karbon elektrot çalışma elektrodu olarak modifiye edilip, kullanılmıştır. Camsı karbon elektrot tek başına OST'nin varlığını algılayamaz. Bu nedenle, OST ile etkileşime girdiği belirlenen ve DNA yapısında bulunan guanin bazı, ajan olarak kullanılmıştır. Camsı karbon elektroda, bir çapraz bağlayıcı olan glutardialdehit kullanılarak DNA yapısında bulunan guanin bazı immobilize edilmiştir (GA2–Guanin/CKE elektrodu). OST'nin elektrokimyasal olarak analizine olanak sağlayan sensör, hızlı, düşük maliyetli ve yüksek doğruluk derecesine sahip analiz olanağı sunmuştur. Diferansiyel puls voltametrisi tekniği kullanılarak, Britton‒Robinson tamponu (BR; pH 11,0) içerisinde yaklaşık +0,45 V'da (Ag/AgCl'ye karşı) iyi tanımlanmış tersinmez bir yükseltgenme sinyali analiz için kullanılmıştır. Geliştirilen bu elektrot ve yöntem, farmasötik formülasyonda ve insan idrar numunelerinde bulunan OST miktarını bulmak için başarıyla uygulanmıştır. BR tampon çözeltisi, tablet numunesi ve idrar numunesi için iki çalışma aralığı saptanmış olup, LOD değerleri sırasıyla 7,16×10−9 mol·L−1, 9,05×10−9 ve 6,19×10−6 mol·L−1 olarak hesaplanmıştır. Önerilen sensör için geri kazanım oranı %86,6‒%103,5 aralığında değişmektedir.

  İncele
• MakaleYalnız künye2023Scopus SJRQ2/r/munzur/2562
  A novel electrochemical sensor for metoprolol analysis based on glutardialdehyde–zinc oxide modified boron doped diamond electrode

  Koçak, Berna; İpek, Yeliz; Keçeci, Ali

  In this study, glutardialdehyde–zinc oxide modified boron doped diamond electrode (GA2–ZnO/BDDE) was developed as a new electrochemical sensor for the rapid, sensitive and selective determination of metoprolol (MTP). By using boron doped diamond electrode (BDDE), glutardialdehyde modified boron doped diamond electrode (GA2/BDDE) and glutardialdehyde–zinc oxide modified boron doped diamond electrode (GA2–ZnO/BDDE) separately, the electrochemical behavior of MTP on the surfaces of these electrodes was determined by applying cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. According to the results, the linear working range was 9.99 × 10−7–3.85 × 10−5 mol·L−1 and the limit of detection (LOD) was 7.53 × 10−8 mol·L−1 in pH 7 Britton–Robinson buffer solution. In addition, intraday reproducibility of peak current and peak potential were measured on the GA2–ZnO/BDDE surface and the results were calculated as 0.56 and 1 (RSD%), respectively. In order to investigate the reproducibility of GA2–ZnO/BDDE, 5 different modified electrodes were prepared with the same composition and conditions. The interday repeatability of the modified electrode was calculated as 3.13 (RSD%) and 1.05 (RSD%) for interday peak current and peak potential, respectively. The applicability of this method was confirmed by analysis of commercial drug tablets containing MTP as active ingredient. The mean recovery of the developed sensor was 95.6 % ± 1.7.

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  AtıfScopus14·WoS12·OpenAlex13

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