Search results for "Chemical detection"
showing 5 items of 15 documents
Polarographic determination of tyrosinase activity in enzymatic reaction with tyrosine as a substrate
2003
A voltammetric investigation of tyrosinase activity is proposed as an alternative to the spectrophotometric method. Voltammetric approach provides low detection limit, high sensitivity and resistivity to the solution inhomogenity, as well as enables one to simultaneously monitor the dioxygen consumption in the reaction, which is an additional indicator of the tyrosinase enzymatic activity.
NiO@Ni core shell for electrochemical detection of Hg ions
2018
Heavy metals are considered as one of the most dangerous chemicals for human health. Among heavy metals, mercury is one of the most dangerous one: few ppb of Hg can cause serious damages to brain, heart, lungs and kidney. The Environmental Protection Agency setted the maximum concentration of Hg in water as 2 ppb [1] . Nowadays is very important to develop new and novel sensors for heavy metals that could be cheap, easy to use and for in-situ and real-time analysis and in this context electrochemical sensors are perfect candidates [2] . The more powerful electrochemical tequinique is Square Wave Anodic Strippic Voltammetry (SWASV), a two step techinique were the heavy metals are first depos…
Data from: Quality attracts parasites: host condition-dependent chemo-orientation of trematode larvae
2014
1. Environmental factors impairing physiological condition of organisms are assumed to predispose them to parasite infections. This is because host immune function is typically condition-dependent. However, poor physiological condition has been reported to reduce host susceptibility to parasites in various systems. 2. We examined whether such an effect can be due to altered exposure of hosts to active parasite transmission stages by investigating chemo-orientation of free-swimming cercariae larvae of a parasite Echinoparyphium aconiatum towards its snail host Lymnaea stagnalis. 3. We used both long-term and short-term feeding treatments to manipulate the body condition and physiological tra…
Asymptotic modeling of electrochemical signaling: Testing Zn in urine for non-invasive bladder cancer diagnosis
2021
Abstract A theoretical model on chemical signaling for diagnosis based on the combination of signals for marker and inert and/or interfering metabolites is described. The model yields asymptotic relationships between the intensities of the signals representative of marker and accompanying metabolites compensating concentration fluctuations. The model fits well with voltammetric features associated to the oxidation of different urine metabolites and Zn(II) reduction in the same urine samples after alkaline digestion. As a result, a non-invasive electrochemical detection of urothelial carcinoma (bladder cancer, BC) is reported. Different diagnostic criteria are described all displaying high s…
Electrochemical detection and screening of bladder cancer recurrence using direct electrochemical analysis of urine: A non-invasive tool for diagnosis
2018
Although detection of urothelial cell carcinoma (or bladder cancer, BC) can be performed via cytological, molecular and genetic marker tests on urine, cystoscopy, an invasive technique, still remains as the gold methodology in clinical practice. It is presented a non-invasive method for detecting BC recurrence consisting of a direct electrochemical test in urine combining voltammetric data at gold and glassy carbon electrodes. The diagnosis is based on the ratio between characteristic voltammetric features recorded for tryptophan, serotonin and melatonin and other related metabolites. The method was tested by means of a clinical trial with 30 patients diagnosed of bladder cancer and a two c…