Investigation of HL porphyrin with dsDNA by electrochemical and spectroscopic techniques: Biosensor studies

The researched of biological properties of porphyrins are a very promising tool for the investigation and study of the action of HL (porphyrin compound; C₉₆H₆₃BrN₁₀O) specifically designed to interact with fish sperm double strain deoxyribonucleic acid (FSdsDNA). The electro-oxidation/reduction mechanism of HL at a glassy carbon electrode (GCE) was studied using various voltammetric techniques. The effects of pH and scan rate on HL signal were determined in detail by cyclic (CV) and differential puls voltammetry (DPV). The possible redox pathway was also proposed. For a better understanding of the interaction mechanism between HL and FSdsDNA, spectroscopic techniques also were performed. The fastening constant (Kb) between HL and FSdsDNA was calculate for electrochemical, UV-vis and fluorescence spectroscopic techniques, respectively. The fastening constant (Kb) between HL and FSdsDNA was calculated as 3.50 × 106 M^-1, 1.30 × 106 M^-1 and 4.03 ×105 M^-1 for electrochemical, UV-vis spectrophotometric and fluorescence spectroscopic techniques, respectively. Last of all, based on all methods, it was confirmed that HL could intercalate into the FSdsDNA helix. Competitive experiments with 3,8-Diamino-5-etil-6-fenilfenantridinium bromide (EtBr) have indicate that the HL exposition the ability to eject the deoxyribonucleic acid-bound EtBr showing that the HL bind to fish sperm double strain deoxyribonucleic acid likely over intercalation in mighty rivalry with EtBr for the intercalative fastening mode.