A sensor for detecting lead in an aqueous solution includes a copper working electrode, a counter electrode, a power supply for applying underpotential deposition of lead onto the copper electrode, a measuring device for providing measurement of a hydrogen evolution reaction (HER) current on the Pb.sub.upd-modified electrode, and a controller configured to correlate the degree of suppression of the HER current to Pb.sub.upd coverage to determine the lead coverage and lead concentration of the solution.

A sensing device including a transistor, at least one response electrode, and a selective membrane is provided. The transistor includes a gate end, a source end, a drain end, and a semiconductor layer, wherein the source end and the drain end are located on the semiconductor layer, and the gate end is located between the source end and the drain end. The at least one response electrode is disposed opposite to the gate end of the transistor and spaced apart from the transistor. The selective membrane is located on the at least one response electrode or on the transistor.

A trace metal analysis detector and method of operating the same to detect metals in various fluid samples using boron doped diamond working electrodes.

The present invention provides derivatized indicator compounds, such as pH indicator compounds, which can be covalently immobilized to a variety of solid substrates to produce an indicator pad. Such pads can be used to monitor water quality in variety of settings. In particular, the pads of the invention are useful in devices which monitor the quality of recreational water, such as water in swimming pools, hot tubs, and amusement park attractions, including water slides, and water-based rides. The present invention overcomes the limitations of commercially available pad chemistries.

A fluorescent nanocomposite which includes a thallium doped gadolinium chalcogenide having formula Tl.sub.xGd.sub.1-xY, wherein x is 0.01 to 0.1, and Y is selected from the group consisting of S, Se, or Te, and a benzothiazolium salt bound to a surface of the thallium doped gadolinium chalcogenide. A method of detecting antimony ions in a fluid sample whereby the fluid sample is contacted with the fluorescent nanocomposite to form a mixture, and a fluorescence emission profile of the mixture is measured to determine a presence or absence of antimony ions in the fluid sample, wherein a reduction in intensity of a fluorescence emissions peak associated with the fluorescent nanocomposite indicates the presence of antimony ions in the fluid sample.

A sensor device is for detecting metal. The sensor device may have a substrate, an electrode on the substrate, and a biopolymer-metal composite film on the electrode. The biopolymer-metal composite film may include a metal and a biopolymer. The sensor device may further have circuitry coupled to the electrode and configured to apply a sensing signal to the electrode.

Disclosed is a real-time method for detecting copper and silver in water in parts per billion. Total silver is detected by adding a nitric acid solution to the sample; after the silver is digested, adding a buffer solution comprising water, sodium bicarbonate, sodium carbonate and EDTA to the sample; adding an indicator comprising Cadion 2B, EtOH, and Triton X-100 to the sample; then reading the absorbance of the sample after light with an approximate target peak of 515 nm is sent through the sample; and determining the silver concentration by comparing the absorbance of the sample to the absorbances of known silver standards. Total copper is detected by adding a nitric acid solution to the sample; after the copper is digested, adding a buffer/indicator solution to the sample, where the solution comprises water, sodium citrate dihydrate, hydroxal amine hydrochloride and bathocuproine disulfonate; after one minute, reading the absorbance of the sample after light with an approximate target peak of 480 nm is sent through the sample; and determining the copper concentration by comparing the absorbance of the sample to the absorbances of known copper standards. A monitoring device for determining the level of copper or silver in a sample implements the disclosed methods.

A fluorescent nanocomposite which includes a thallium doped gadolinium chalcogenide having formula Tl.sub.xGd.sub.1-xY, wherein x is 0.01 to 0.1, and Y is selected from the group consisting of S, Se, or Te, and a benzothiazolium salt bound to a surface of the thallium doped gadolinium chalcogenide. A method of detecting antimony ions in a fluid sample whereby the fluid sample is contacted with the fluorescent nanocomposite to form a mixture, and a fluorescence emission profile of the mixture is measured to determine a presence or absence of antimony ions in the fluid sample, wherein a reduction in intensity of a fluorescence emissions peak associated with the fluorescent nanocomposite indicates the presence of antimony ions in the fluid sample.

The present invention relates to a device for detecting concentration of heavy metals. The device for detecting concentration of heavy metals acquires spectrum information of a carrier to be tested by utilizing a spectrum information acquiring system, a receiving system and a processing system. The device further processes the spectrum information to obtain the type of the carrier to be tested and the corresponding concentration of heavy metals. Therefore, the efficiency of acquiring the whole concentration of the heavy metals is remarkably improved. Furthermore, based on the specific structure of the device for detecting concentration of heavy metals provided by the present invention, the device for detecting concentration of heavy metals has the characteristics of simple structure and low costs.

A method of validating a water determining device includes the steps of providing a liquid water standard including a room temperature ionic liquid, adding the liquid water standard to the water determining device, and determining the amount of water in the liquid water standard utilizing the water determining device thereby validating the water determining device.