Carcinogens electrochemical detection

For a more detailed overview of electrochemical detection, the interested reader is referred to Kissinger [59]. The range of applications snitable for electrochemical detection are discnssed in an excellent review by Pacakova and Stulik [60]. Perhaps the most biomedically important application is the determination of catecholamines in bioflnids [61-63]. Electrochemical detection has also lent itself to the detection of other medically important amines snch as histamine [64] and nenrotrans-mitters [65]. Additionally, electrochemical detection has been applied to the detection of certain antibiotics [66] and environmental carcinogens [67]. 

The haloacetic acids (HAA) are comprised of mono-, di- and trichloroacetic acid, mono-, di-, and tribromoacetic acid, and bromo-chloroacetic acid, bromo-dichloroacetic acid, and dibromo-chloroacetic acid. Toxicological studies showed that these compounds have carcinogenic properties and may have adverse reproductive consequences. HAA have no strong chromophore for sensitive UV detection electrochemical detection has been described. Analysis by GC-MS requires derivatization. Due to their relatively low molecular mass, the LC-MS analysis can be hindered by low-mass background interferences. 

Barek, J., V. Pacakova, K. Stulik, and J. Zima. 1985. Monitoring of aromatic amines by HPLC with electrochemical detection. Comparison of methods for destruction of carcinogenic aromatic amines in laboratory wastes. Talanta 52(4) 279-83. 

One of the potential applications of DNA electrochemical sensor is its capability of detecting the presence of toxic analytes (e.g., carcinogens, drugs, mutagenic... 

Nitrite Nitrite is an important indicator of fecal pollution in natural waters as well as a potential precursor of carcinogenic species. A rush of flow and sequential injection spectrophotometric method based on Griess-type reactions has been proposed, also coupled to online sorbent enrichment schemes. The catalytic effect of nitrite on the oxidation of various organic species constitutes the basis of fairly sensitive spectrophotometric methods. Fluorometric methods based on the formation of aromatic azoic acid salts, quenching of Rhodamine 6G fluorescence, and direct reaction with substituted tetramine or naphthalene species have been also reported. Indirect CL methods usually involve conversion into nitric oxide and gas-phase detection as mentioned in the foregoing section. The redox reaction between nitrite and iodide in acidic media is the fundamental of a plethora of flow injection methodologies with spectrophotometric, CL, or biamperometric detection. New electrochemical sensors with chemically modified carbon paste electrodes containing ruthenium sites, or platinum electrodes with cellulose or naphthalene films, have recently attracted special attention for amperometric detection. 

The development and characterization of a DNA-electrochemical biosensor provides very relevant information because the mechanisms of DNA-hazard compound interaction at charged interfaces mimic better the in vivo situation. The detection of chemical compounds that cause irreversible damage to DNA is very important, as they may lead to hereditary or carcinogenic diseases. Reactions with chemical substances cause changes in the structure of DNA and the base sequence leading DNA oxidative damage and to perturbations in DNA replication. 

It has been shown in this chapter that the DNA-modified electrodes (electrochemical DNA biosensors) already represent very effective and, at the same time, simple, fast, inexpensive, miniaturized, and mass-producible analytical devices for evaluation and classification of modes of genotoxic effects of individual xenobiotic compounds (e.g., chemical carcinogens, pesticides, dmgs, dyes, or reactive radical species), as well as for prescreening of new drugs and newly synthesized chemicals. Moreover, the evaluation of DNA protection capacity of various natural and synthetic chemical substances (antioxidants) is also possible using the detection of DNA damage caused by prooxidants. 

Blaskova M (2012) Novel electrochemical biosensor for the detection of DNA damage caused by chemical carcinogens. B.Sc. thesis, Charies University in Prague, Prague... 

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