Real-time Detection of Trace Copper in Brain and Kidney of Fish for Medical Diagnosis.

For the detection of trace copper to be used in medical diagnosis, a sensitive handmade carbon nanotube paste electrode (PE) was developed using voltammetry. Analytical optimized conditions were found at 0.05 V anodic peak current. In the same conditions, various common electrodes were compared using stripping voltammetry, and the PE was found to be more sharply sensitive than other common electrodes. At optimum conditions, the working ranges of 3~19 µgL(-1) were obtained. The relative standard deviation of 70.0 µgL(-1) was determined to be 0.117% (n = 15), and the detection limit (S/N) was found to be 0.6 µgL(-1) (9.4 × 10(-9) M). The results were applied in detecting copper traces in the kidney and the brain cells of fish.

Detection of trace metal in distilled alcoholic drinks.

The presence of trace metal cadmium assay was investigated with a copper immobilized on a graphite carbon electrode (GPC), the modified property of which was determined with handheld voltammetric systems. Following the determination of the analytical stripping conditions of 0.45 V amplitude, 30 Hz frequency, -1.4 V initial potential, and 4.0 mV increment potential, only a 60-s experimental accumulation time was used. Using these conditions, the analytical detection limit approached the nano range. At this condition, the analytical application was performed on distilled alcoholic drinks for food manufacturing systems. This developed technique is faster and less costly than the common voltammetric and spectrophotometric methods.

Diagnostic Assay of Toxic Zinc in an Ex vivo Cell Using Voltammetry.

Voltammetric detection of the toxic Zn ion was investigated using a fluorine-doped graphite pencil electrode (FPE). It is notable from the study that pencils were used as reference and working electrodes. In all the experiments, a clean seawater electrolyte solution was used to yield good results. The analytical working range was attained to 10 µgL(-1). The optimized voltammetric condition was examined to maximize the effect of the detection of trace Zn. The developed sensor was applied to an earthworm's tissue cell. It was found that the methods can be applicable to in vivo fluid or agriculture soil and plant science.

Diagnosis of Helicobacter pylori bacterial infections using a voltammetric biosensor.

The voltammetric assay of Helicobacter pylori DNA was investigated using a bismuth-immobilized carbon nanotube electrode (BCNE). The analytical cyclic voltammetry (CV) peak potential was obtained at a 0.4V reduction scan, where the diagnostic optimum square-wave (SW) stripping working range was achieved at 0.72-7.92 µg/mL H. pylori DNA (11 points). A relative standard deviation of 1.68% (RSD, n=5) was obtained with 3.2 mg/mL H. pylori DNA using a 240 s accumulation time. Under optimum conditions, detection limit was 0.06 µg/mL. The developed sensors can be used for clinical application in the 15th doubted human gastric tissues, since the patient's peak current increased a hundred times more than the negative healthy tissue did. The sensing time obtained was only two minutes, and the process was simpler compared to common PCR amplification and electrophoresis photometric detection systems.

Diagnostic assay of trace lead in an ex vivo tissue using a combination electrode.

A voltametric diagnosis of trace lead was performed using macro type combination sensors of fluorine-doped graphite pencil electrodes (FPE). Two pencils were used as the reference and auxiliary instead of expensive Ag/AgCl standards and Pt counters. Under optimized conditions, a square wave (SW) stripping working curve was attained at 10-70 mg/L and a micro range of 10-70 µg/L. The developed sensor was not only inexpensive but also had a fast (90-s) accumulation time. An analytical detection limit of 10 µg/L was obtained. The results were applied to an ex vivo tissue and an artificial turf.

Assay of In Vivo Chromium with a Hollow-fiber Dialysis Sensor.

The analytical in vivo chromium ion was searched for using a voltammetric hollow-fiber dialysis sensor via square wave stripping voltammetry (SW) , cyclic voltammetry (CV) , and chronoamperometry. Under optimum parameters, the analytical results indicated linear working ranges of 50~400 mg/l CV and 10~80 µg/l SW within a 30-sec accumulation time. The analytical detection limit (S/N) was 6.0 µg/l. The developed method can be applied to in vivo tissues and in ex vivo toxicity assay, as well as to other materials that require chromium analysis.