Dendrimer modified graphite sensors for detection of anticancer drug Daunorubicin by voltammetry and electrochemical impedance spectroscopy.

The development of amino-terminated G4 PAMAM dendrimer (PDR) modified disposable electrodes were developed as the first time in our study by using the dendrimer modified disposable graphite (PDR-PGE) and multiwalled carbon nanotube based screen-printed graphite (PDR-MWCNT-SPE) electrodes. Firstly, the microscopic characterization of bare PGEs and PDR modified PGEs was performed. These sensors were then applied for electrochemical monitoring of an anticancer drug, Daunorubicin (DNR). The enhanced oxidation signal of DNR was measured at +0.50 V by using differential pulse voltammetry (DPV) in combination with the PDR-PGEs. The detection limit, estimated from S/N = 3, corresponds accordingly to 317 nM and 128 nM for DNR respectively at the PGE and PDR-PGE. The voltammetric results were consistent with electrochemical impedance spectroscopy (EIS) that was used to characterize the successful modification of PDR onto the surface of PGE and MWCNT-SPE.

Electrochemical behaviour of carbon paste electrodes enriched with tin oxide nanoparticles using voltammetry and electrochemical impedance spectroscopy.

The effect of the SnO(2) nanoparticles (SNPs) on the behaviour of voltammetric carbon paste electrodes were studied for possible use of this material in biosensor development. The electrochemical behaviour of SNP modified carbon paste electrodes (CPE) was first investigated by using cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. The performance of the SNP modified electrodes were compared to those of unmodified ones and the parameters affecting the response of the modified electrode were optimized. The SNP modified electrodes were then tested for the electrochemical sensing of DNA purine base adenine to explore their further development in biosensor applications.

Electrochemical monitoring of the interaction between 4-nonylphenol and DNA by graphite and carbon nanotube modified graphite electrodes.

The interaction of 4-nonylphenol (NP) with deoxyribonucleic acid (DNA) was explored electrochemically by using differential pulse voltammetry (DPV) in combination with unmodified and modified pencil graphite electrodes (PGE) with single walled carbon nanotubes (SWCNT). The differentiation of the two oxidation signals coming from NP and DNA base, guanine was studied before and after the interaction process. In addition, the effect of NP concentration was investigated in order to determine the optimum experimental conditions. The detection limit and the reproducibility were determined by using CNT-modified electrodes.

Electrochemical investigation of interactions between potential DNA targeted compounds, 2,4-di- and 2,3,4-trisubstituted benzimidazo[1,2-a]pyrimidines and nucleic acid.

The electrochemical aspects of interactions between DNA and two organic compounds are discussed herein. Potential DNA targeted compounds, 2-methyl-4-phenyl-benzo[4,5]imidazo[1,2-a]pyrimidine (C1) and 2,3,4-trimethyl-benzo[4,5]imidazo[1,2-a]pyrimidine (C2), were synthesized and their cytotoxic and/or growth inhibitory effects were studied previously. Disposable sensor technology was used to explore the interaction between the compounds and nucleic acid, such as fish sperm DNA at the electrode surface and in the solution phase. The changes upon encountering oxidation signals of electroactive DNA base-guanine and these compounds were monitored electrochemically.