Diagnostic assay of chromium (VI) in the ex vivo fluid of the urine of a smoker using a fluorine‐doped handmade sensor

Abstract

A voltammetric diagnosis of a chromium (VI) ion was investigated using a fluorine-doped graphite pencil electrode. Square wave (SW) stripping working conditions were attained at a high range of 0.051-0.45 mg L(-1) and a microrange of 0.05-0.4 microg L(-1) in a 0.1 M NH(4)H(2)PO(4) electrolyte solution, at a relative standard deviation of 1.68% (RSD, n=15), using 10.0 microg L(-1) Cr(VI). A fast experimental time was used only for the 120 sec SW accumulation time. An analytical detection-limit (DL) of 0.008 microg L(-1) was attained. DL appeared to be more sensitive than common voltammetric and spectrophotometric assays. The developed sensor was applied to tap water and the urine of a smoker. It was found that the methods can be applicable for in vivo fluid or medicinal diagnosis.

Pencil Graphite Electrodes: A Versatile Tool in Electroanalysis

“…A fluorine doped PGE applied to Cr(VI) detection in tap water and smoker urine was obtained by CV in HF solution when fluorinated graphite structures were formed. In SWV the electrode presented two linear ranges, namely, 0.051–0.45 mg·L −1 and 0.05–0.4 μ g·L −1 , and a LD of 0.008 μ g·L −1 Cr(VI) [ 196 ], whereas a PGE modified by adsorption of quercetin [ 192 ] or hematoxylin [ 197 ] exhibited improved electrocatalytic response for sulfide with linear ranges of 1–20 μ M and 20–800 μ M and a LD of 0.3 μ M and 1–200 μ M and 0.4 μ M sulfide, respectively. An ETPGE modified by adsorption of quercetin was sensitive to reduced β -nicotinamide adenine dinucleotide (NADH) in the range 0.5–100 μ M with a LD of 0.15 μ M. Based on CV data an ECE mechanism was proposed for the electrocatalytic oxidation of NADH [ 193 ].…”

Colloidal gold nanoparticle probe-based immunochromatographic assay for the rapid detection of chromium ions in water and serum samples

“…A number of methods have been reported for the detection of metal ion, such as dispersive liquid-liquid microextraction and dried-droplet laser ablation ICP-MS[6], carbon composite-PVC based membrane coated platinum electrode[4], amperometric enzyme-based sensor[7], flame atomic absorption spectrometry[8], fluorine-doped graphite pencil electrode[9] and nano-Au/TiO2 photocatalysis reduction device[10]. Despite the high sensitivity and specificity that can be achieved by these methods, they require professional staff and expensive equipment that are difficult to use on-site.…”

Investigation of Trace Cobalt in Glass Beads From an Archaeological Tomb

“…For the voltammetry, two kinds of working sensors were prepared using a pencil-type graphite carbon electrode (PE) measuring 0.5 mm in diameter and 60 mm in length (Type B, Pentel Company, Ltd.) [18]. DNA (double-stranded calf 1530-437X/$26.00 © 2010 IEEE thymus sigma reagent) immobilized on a single-walled carbon nanotube graphite powder (Nanostructured and Amorphous Materials, Inc.) (DCNE) sensors were prepared by mixing with DNA 20%, single-walled carbon nanotube powder 20%, and reagent grade mineral oil (1-800-01, Acro) using a 20% mixed (6 : 2 : 2 weight ratio) paste was inserted into a 3-mm diameter, 100-mm long capillary glass tube using a copper wire connected to the voltammetry workstations.…”