Electrochemical detection of in situ adriamycin oxidative damage to DNA.

TLDR: The results showed that the interaction of adriamycin with DNA is potential-dependent causing contact between DNA guanine and adenine bases and the electrode surface such that their oxidation is easily detected.

About: This article is published in Talanta.The article was published on 2002-04-01 and is currently open access. It has received 127 citations till now. The article focuses on the topics: Guanine & DNA.

Figures

Fig. 6. Background-subtracted differential pulse voltammograms in normal atmosphere in pH 4.5 0.1 M acetate buffer: (···) bare GCE in a 1 M adriamycin solution; (— ) thick layer of dsDNA-modified GCE after being immersed in a 1 M adriamycin solution during 10 min and rinsed with water before the experiment and transferred to buffer. Pulse amplitude 50 mV, pulse width 70 ms, scan rate 5 mV s−1.

Fig. 9. Background-subtracted differential pulse voltammograms in a dsDNA 60 g ml−1 solution in pH 4.5 0.1 M acetate buffer obtained with: a bare GCE (·-·-·) after applying a potential of −0.6 V during 60 s; and an adriamycin adsorbed-modified GCE: (···) first scan with no potential applied; (---) after applying a potential of 0.0 V during 60 s; (— ) after applying a potential of −0.6 V during 60 s. Pulse amplitude 50 mV, pulse width 70 ms, scan rate 5 mV s−1.

Fig. 1. Cyclic voltammogram of 5 M adriamycin in pH 4.5 0.1 M acetate buffer obtained with a GCE. Scan rate: 2 V s−1. Ei=0.0 V.

Fig. 2. Background-subtracted differential pulse voltammograms of 1 M adriamycin in pH 4.5 0.1 M acetate buffer at a bare GCE: normal atmosphere (— ); saturated with O2 (···) and N2 (---). Pulse amplitude 50 mV, pulse width 70 ms, scan rate 5 mV s−1.

Fig. 7. Background-subtracted differential pulse voltammograms in pH 4.5 0.1 M acetate buffer obtained with a thick layer dsDNA-modified GCE after being immersed during 10 min in a 1 M adriamycin solution and rinsed with water before the experiment in buffer: (···) without applied potential; (— ) subsequent scan after applying a potential of −0.6 V during 120 s. Pulse amplitude 50 mV, pulse width 70 ms, scan rate 5 mV s−1.

Fig. 4. Differential pulse voltammograms obtained with a bare GCE in pH 4.5 0.1 M acetate buffer of: (···) 15 M 8-oxoG; (···) 15 M guanine (G); (···) 15 M guanosine (Guo); (···) 100 M adenine (A); and 60 g ml−1 dsDNA (---) first and (— ) 40th voltammogram. Pulse amplitude 50 mV, pulse width 70 ms, scan rate 5 mV s−1.

Frequently asked questions

Q1. What have the authors contributed in "Electrochemical detection of in situ adriamycin oxidative damage to dna" ?

Adriamycin intercalation and in situ interaction with double helix DNA was investigated using a voltammetric DNA-biosensor. A mechanism for adriamycin reduction and oxidation in situ when intercalated in double helix DNA immobilised onto the glassy carbon electrode surface is presented and the formation of the mutagenic 8-oxoguanine explained. The results showed that the interaction of adriamycin with DNA is potential-dependent causing contact between DNA guanine and adenine bases and the electrode surface such that their oxidation is easily detected. 

Q2. What software was used for the presentation of the experimental voltammograms and graphs?

ORIGIN (version 6.0) from Microcal Software was used for the presentation of all the experimental voltammograms and graphs reported in this work. 

Q3. What is the potential use of dsDNA film-modified GCE?

The potential use of this DNA film-modified GCE for the understanding of DNA interactions with molecules or ions explores, in a promising way, the use of voltammetric techniques for in situ generation of reactive intermediates and is a complementary tool for the study of biomolecular interaction mechanisms. 

Q4. What is the effect of adriamycin on the oxidation of DNA?

Since the experiments were carried out in buffer, the peaks recorded for the reduction or oxidation of adriamycin can only be attributed to the reaction of adriamycin molecules that are inside the thick film of dsDNA. 

Q5. What is the role of the -stacked base pairs in the oxidative damage of double?

the -stacked base pairs characteristic of double helix DNA might serve as a pathway for charge transport [33,34] mediating the redox reaction between adriamycin radicals, generated during reduction, and guanine residues in the double helix. 

Q6. How long does it take to prepare an adriamycin GCE?

An adriamycin adsorbed-modified GCE could be prepared by immersing the electrode in an adriamycin solution for a short period of time with or without deposition potential applied. 

Q7. how was the adriamycin confined to the electrode surface?

At the adriamycin adsorbed-modified GCE, adriamycin was confined to the electrode surface and the total surface concentration of adriamycin was calculated using,adr=4RTIp,a/n2F2A ,to be adr=2.57×10−10 mol cm−2 [27]. 

Q8. What is the drawback of the thin layer dsDNA-modified GCE?

In fact, this is the drawback of the thin layer dsDNA-modified GCE since it leads to two contributions from simple adsorbed analyte and damage to immobilised DNA which needs to be carefully distinguished. 

Q9. Why is the adriamycin interaction performed in contact with normal atmosphere?

This is important because all the oxidation studies and the electrochemical detection of adriamycin interaction with dsDNA are carried out in contact with normal atmosphere. 

Q10. What is the chemical activity of adriamycin intercalated with DNA?

Electrochemical activity for the adriamycin structurally related compound daunomycin intercalated with DNA was also observed using a carbon paste electrode [21]. 

Q11. What was the effect of the adriamycin on the GCE?

An abrupt decrease in peak current was always observed in the second scan, Fig. 5b, suggesting a fast consumption of the adriamycin on the surface.