Potentiometric and voltammetric polymer lab chip sensors for determination of nitrate, pH and Cd(II) in water

Abstract

Due to their toxicity to humans and animals, heavy metals and nitrate in groundwater are of particular concern. The combination of high toxicity and widespread occurrence has created a pressing need for effective monitoring and measurement of nitrate and heavy metals in soil pore water and groundwater at shallow depths. In this work, a new electrochemical sensing platform with the self-assembly nanobeads packed (nBP) hetero columns has been developed for the pH and nitrate measurements. In addition, for on-site determination of cadmium (Cd(II)), a bismuth (Bi(III)) based polymer lab chip sensor using the square-wave anodic stripping voltammetry (SWASV) sensing principle has been designed, fabricated and successfully characterized. Factors affecting sensitivity and precision of the sensor, including deposition potential and deposition time, were studied. Miniaturized electrochemical lab chip sensors could be very valuable in environmental monitoring area due to their many benefits, such as greatly reduced sensing cost, sensing system portability, and ease of use.

Circadian rhythms in Neurospora crassa on a polydimethylsiloxane microfluidic device for real-time gas perturbations

“…A polymer master mold containing microchannels was fabricated using a previously developed method in our lab. 19,20 Using a patterned transparency film mask, a commercially available printing press plate with a 1.05 mm thick photosensitive polymer (WA210, Flint Group, OH) was exposed to diffuse ultraviolet (UV) light (1 J/cm 2 , 365 nm). Then, the exposed printing plate was developed FIG.…”

Applications of autonomous microfluidic systems in environmental monitoring

“…The second device was an adaptation to detect Cd(II). 11 The device has a similar aspect to the one previously described, but has just two groups of three electrodes. LOD was 9.3 ppb, using deposition at 21.2 V for 90 s, and detection between 21.2 and 20.5 V. The authors evaluated Pb(II) interference and observed that the peak current is 20.85 and 20.58 V for Cd (II) and Pb(II), respectively.…”

“…This change in paradigm can be exemplified by examining the works of Ahn's group. [9][10][11][12][13] Their first paper presented a disposable heavy metal detector, but three years later they published an FDS for the same application, using similar strategies.…”

Continuous Monitoring of Soil Nitrate Using a Miniature Sensor with Poly(3-octyl-thiophene) and Molybdenum Disulfide Nanocomposite

“…This solution was sealed and stored at -20 °C. 52 Nanocomposite of POT-MoS2: The weight ratio of POT to MoS2 was varied from 1:1 to 1:10 to study the influence of material composition on the redox properties of different POT-MoS2 nanocomposites. In each case, the concentration of POT solution was fixed at 2.6 mg/mL.…”